Re: [Tutor] Do you use unit testing?
"Modulok" wrote How many of you guys use unit testing as a development model, or at all for that matter? Personally I use unit testing for anything that I'm getting paid for Occasionally I use it for something I'm doing for myself, but only if its quite big - several modules and over say, 500 lines of code. So for small single-file utilities etc that I only use myself I wouldn't bother. I just starting messing around with it and it seems painfully slow to have to write a test for everything you do. Its a lot more painful and slow to have to debug subtle faults in code you wrote 6 months ago and that don't throw exceptions but just quietly corrupt your data... The real benefits of unit tests are: a) You test stuff as you write it so you know where the bug must lie b) You can go back and run the tests again 6 months later, c) if you have to add a new test its easy to make sure you don't break what used to work (regression testing). HTH, -- Alan Gauld Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Do you use unit testing?
"Stephen Nelson-Smith" wrote As a discipline - work out what we want to test, write the test, watch it fail, make it pass - I find this a very productive way to think and work. Warning: It can be seductively addictive and lead to very bad code structure. You start focussing on just passing the test rather than the overall structure and design of the solution. Make sure that once it passes the tests you go back and refactor the code to be clean and maintainable. Then test it again of course! HTH, -- Alan Gauld Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] pyce, scripts complete too fast
"rick" wrote Now I'm back to the problem that a Windows newbie would have, the scripts complete before I can see what happened! I can get right to the interactive mode, or I can run a script, but not sure where I'd find the terminal. Have a look at the "Note for Windows Users" in the Topic Add a little style in my tutorial. It offers several ways of dealing with this issue. -- Alan Gauld Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Do you use unit testing?
Le Mon, 16 Nov 2009 13:54:26 -0700, Modulok stated: > List, > > A general question: > > How many of you guys use unit testing as a development model, or at > all for that matter? I do. Systematically. Has become a reflex. I would rather ask the opposite question: how do know a part of your code actually works if you don't test it? What I do not do is writing the tests before developping. Probably because my style of programming is rather "exploratory", or incremental: I discover and expand while developping, so that I cannot predict what a relevant test may be. Test-driven development relies on full, accurate, detailed specification even before design; actually pre-development test code forms a kind of specif. > I just starting messing around with it and it seems painfully slow to > have to write a test for everything you do. Thoughts, experiences, > pros, cons? Yes, you're right: "it seems painfully slow". It's an illusion. Just like the illusion that writing "user_account" rather than "usr_acnt" will slow your development pace. (I read once that developpers spend less than 1% of their time actually typing.) There's something wrong in humain brains ;-) Writing a test func for a bit of code lets you: * understand your code better * find flaws and bugs before even testing * find remaining flaws and bugs (but not all) * validate your code (mentally, if only for yourself) * validate changes (possibly in other code parts, related to this one) It's much faster and better than letting unfinished code with "bombs" everywhere, that will randomly explode. Especially because numerous bugs won't look like beeing related to their actual source. > Just looking for input and different angles on the matter, from the > Python community. > -Modulok- Good question, imo! Denis * la vita e estrany * http://spir.wikidot.com/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] search the folder for the 2 files and extract out only theversion numbers 1.0 and 2.0.
"MARCUS NG" wrote what is the best way to look into the allFiles directory, and only search the folder for the 2 files myTest1.0.zip and myTest2.0.zip to extract out only the version numbers 1.0 and 2.0. You probably want to use the glob.glob() function to search using a pattern like myTest*.zip. Then you can iterate over the list of names returned and examoine the version number using normal sring functions (or reguar expressions) so I did think of listing the file names in an array only to realise that I wouldn't know which index to query if this script is going to be automated. In Python you hardly ever need to query the index to extract items from a list, instead you use a for loop to look at each item in turn. for filename in glob.glob(pattern): version = extractVersion(filename) # etc... HTH, -- Alan Gauld Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Unexpected Result in Test Sequence
wrote in message I'm running a test to find what the experimental average of a d20 is, and came across a strange bug in my code. import random list1 = [] def p(): d = 0 for number in range(1,1000): t = random.randrange(1,19) list1.append(t) for value in list1: d+=value print d/1000 d = 0 for value in range(1,100): p() It works, but I have a logic error somewhere. It runs, and the results have a pattern : It just adds 10, and every second result, subtracts 1, till it gets to 0, and then starts again with 9 in singles, and whatever in the 10's, etc. I'm not exactly sure what you expect but given you are finding the average of a set of numbers between 1,19 I'd expect the result to be 9.5. In other words the integer value will vary between 9 and 10, which is what is happening. Can you show us a segment of data that manifests the problem more clearly than the set you have included? HTH, -- Alan Gauld Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Do you use unit testing?
Le Tue, 17 Nov 2009 08:01:32 -, "Alan Gauld" stated: Hello, Alan, > The real benefits of unit tests are: > a) You test stuff as you write it so you know where the bug must lie Yes! (tried to say the same much clearly ;-) > b) You can go back and run the tests again 6 months later, > c) if you have to add a new test its easy to make sure you don't break > what used to work (regression testing). Do not understand this point. Would you be kind and expand on this topic? Have never header of regression testing (will google it, but would appreciate you words, too.) (I guess it may be relevant for incremental development.) Denis * la vita e estrany * http://spir.wikidot.com/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Do you use unit testing? PS
Le Tue, 17 Nov 2009 09:56:23 +0100, spir stated: > > b) You can go back and run the tests again 6 months later, > > c) if you have to add a new test its easy to make sure you don't break > > what used to work (regression testing). > > Do not understand this point. Would you be kind and expand on this topic? > Have never header of regression testing (will google it, but would > appreciate you words, too.) (I guess it may be relevant for incremental > development.) Sorry, sent my post too fast: http://en.wikipedia.org/wiki/Regression_testing Denis * la vita e estrany * http://spir.wikidot.com/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] pyce, scripts complete too fast
rick wrote: Perhaps the wrong list, but I'll ask anyway. So I'm in the middle of starting, yet again, to learn some programming. I have 2.6.4 and 3.1 installed on the desktop (Ubuntu 9.10), 2.6.4 installed on the netbook (UNR 9.10). I was thinking to be ultra portable, I'd put python on the pocket pc. Now I'm back to the problem that a Windows newbie would have, the scripts complete before I can see what happened! I can get right to the interactive mode, or I can run a script, but not sure where I'd find the terminal. Thanks Alan, I was going through your old tutorial, the pointer to the new was appreciated. Rick On Windows, you can get a terminal window (aka DOS box) by running "Command Prompt" from your Start menu (In recent versions it seems to be in Start->Accessories). You can copy that shortcut elsewhere, of course. Or you can run CMD.EXE from anywhere, like the Run menu or another DOS box. Once you have a DOS box, you can set local environment variables, run batch files, or do other preparations before beginning your python program. And of course when the python program finishes you can still see the results (with some amount of scrolling, buffer size can be adjusted).And once you're in a DOS box, you can get two independent ones by running Start from the first. The new one inherits environment variables and current directory from the first, but does not block the first one from taking new commands. You can also create a shortcut that starts a new DOS box, AND runs your program. I haven't done this in so long that I forget the syntax. But it's something like cmd.exe /k python.exe script.py By using the right switch on cmd.exe, the DOS box doesn't go away when the python program exits. By the way, you can get rid of a DOS box by typing EXIT at its prompt, or by clicking the X on the upper right corner of the window. DaveA DaveA ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] Use of 'or'
A friend of mine mentioned what he called the 'pythonic' idiom of: print a or b Isn't this a 'clever' kind or ternary - an if / else kind of thing? I don't warm to it... should I? S. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Use of 'or'
Stephen Nelson-Smith wrote: A friend of mine mentioned what he called the 'pythonic' idiom of: print a or b Isn't this a 'clever' kind or ternary - an if / else kind of thing? I would say it's perfectly idiomatic in Python, but not as a ternary. If you want a ternary use the (relatively) recently-introduced: a if else b eg: things = [1, 2 ,3] print "%d thing%s found" % (len (things), "" if len (things) == 1 else "s") Before this operator came along, people used to use more-or-less clever-clever tricks with boolean operators or using the fact that bool / int are interchangeable: ['s', ''][len (things) == 1] The "a or b" idiom is most commonly used for default-type situations: def f (a, b=None): print "a", b or "" I don't warm to it... should I? Up to you :) But I regard it as a useful idiom. TJG ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] Introduction - log exercise
Hi everybody,
This is my first post here. I have started learning python and I am new to
programing, just some bash scripting, no much.
Thank you for the kind support and help that you provide in this list.
This is my problem: I've got a log file that is filling up very quickly, this
log file is made of blocks separated by a blank line, inside these blocks there
is a line "foo", I want to discard blocks with that line inside it, and create a
new log file, without those blocks, that will reduce drastically the size of the
log file.
The log file is gziped, so I am going to use gzip module, and I am going to pass
the log file as an argument, so sys module is required as well.
I will read lines from file, with the 'for loop', and then I will check them for
'foo' matches with a 'while loop', if matches I (somehow) re-initialise the
list, and if there is no matches for foo, I will append line to the list. When I
get to a blank line (end of block), write myList to an external file. And start
with another line.
I am stuck with defining 'blank line', I don't manage to get throught the while
loop, any hint here I will really appreciate it.
I don't expect the solution, as I think this is a great exercise to get wet
with python, but if anyone thinks that this is the wrong way of solving the
problem, please let me know.
#!/usr/bin/python
import sys
import gzip
myList = []
# At the moment not bother with argument part as I am testing it with a
# testing log file
#fileIn = gzip.open(sys.argv[1])
fileIn = gzip.open('big_log_file.gz', 'r')
fileOut = open('outputFile', 'a')
for line in fileIn:
while line != 'blank_line':
if line == 'foo':
Somehow re-initialise myList
break
else:
myList.append(line)
fileOut.writelines(myList)
Somehow rename outputFile with big_log_file.gz
fileIn.close()
fileOut.close()
-
The log file will be fill with:
Tue Nov 17 16:11:47 GMT 2009
bladi bladi bla
tarila ri la
patatin pataton
tatati tatata
Tue Nov 17 16:12:58 GMT 2009
bladi bladi bla
tarila ri la
patatin pataton
foo
tatati tatata
Tue Nov 17 16:13:42 GMT 2009
bladi bladi bla
tarila ri la
patatin pataton
tatati tatata
etc, etc ,etc
..
Again, thank you.
--
-
Antonio de la Fuente Martínez
E-mail: t...@muybien.org
-
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Re: [Tutor] Introduction - log exercise
On Tue, Nov 17, 2009 at 10:58 AM, Antonio de la Fuente wrote: > Hi everybody, > > This is my first post here. I have started learning python and I am new to > programing, just some bash scripting, no much. > Thank you for the kind support and help that you provide in this list. > You're welcome! > > This is my problem: I've got a log file that is filling up very quickly, > this > log file is made of blocks separated by a blank line, inside these blocks > there > is a line "foo", I want to discard blocks with that line inside it, and > create a > new log file, without those blocks, that will reduce drastically the size > of the > log file. > > The log file is gziped, so I am going to use gzip module, and I am going to > pass > the log file as an argument, so sys module is required as well. > > I will read lines from file, with the 'for loop', and then I will check > them for > 'foo' matches with a 'while loop', if matches I (somehow) re-initialise the > list, and if there is no matches for foo, I will append line to the list. > When I > get to a blank line (end of block), write myList to an external file. And > start > with another line. > > I am stuck with defining 'blank line', I don't manage to get throught the > while > loop, any hint here I will really appreciate it. > Let me start out by saying this; I'm very impressed with the thought you've put into the problem and the way you've presented it. The first thing that pops into my mind is to simply strip whitespace from the line and check if the line == ''. Upon further experiment there's the "isspace" method: In [24]: x = ' \n\n\r\t\t' In [25]: x.isspace() Out[25]: True x contains a bunch of spaces, newlines, and tab chars. From the docs: " Return True if all characters in S are whitespace and there is at least one character in S, False otherwise." > I don't expect the solution, as I think this is a great exercise to get wet > with python, but if anyone thinks that this is the wrong way of solving the > problem, please let me know. > > for line in fileIn: >while line != 'blank_line': >if line == 'foo': >Somehow re-initialise myList >break >else: >myList.append(line) >fileOut.writelines(myList) Rather than using a while, you can use an if statement with the space method (and join your statement with an: if not line.isspace() and not line == 'foo': fileOut.write(line) then you can get rid of the whole myList. Based on what you've written, there's really no need to have a list, it's more efficient to just write the line straight to the file. for the renaming part, take a look at the shutil module. HTH, Wayne ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Introduction - log exercise
> I will read lines from file, with the 'for loop', and then I will check them
> for
> 'foo' matches with a 'while loop', if matches I (somehow) re-initialise the
> list, and if there is no matches for foo, I will append line to the list.
> When I
> get to a blank line (end of block), write myList to an external file. And
> start
Can you please explain what you mean by _re-initialize the list_ ?
> with another line.
>
> I am stuck with defining 'blank line', I don't manage to get throught the
> while
> loop, any hint here I will really appreciate it.
> I don't expect the solution, as I think this is a great exercise to get wet
> with python, but if anyone thinks that this is the wrong way of solving the
> problem, please let me know.
>
>
Can you explain why the following won't work?
#!/usr/bin/python
import sys
import gzip
# At the moment not bother with argument part as I am testing it with a
# testing log file
#fileIn = gzip.open(sys.argv[1])
fileIn = gzip.open('big_log_file.gz', 'r')
fileOut = open('outputFile', 'a')
for line in fileIn:
while line != 'blank_line':
if 'foo' not in line:
fileOut.write(line)
>
>
> Somehow rename outputFile with big_log_file.gz
>
> fileIn.close()
> fileOut.close()
>
> -
>
> The log file will be fill with:
>
>
> Tue Nov 17 16:11:47 GMT 2009
> bladi bladi bla
> tarila ri la
> patatin pataton
> tatati tatata
>
> Tue Nov 17 16:12:58 GMT 2009
> bladi bladi bla
> tarila ri la
> patatin pataton
> foo
> tatati tatata
>
> Tue Nov 17 16:13:42 GMT 2009
> bladi bladi bla
> tarila ri la
> patatin pataton
> tatati tatata
>
>
> etc, etc ,etc
> ..
>
> Again, thank you.
>
> --
> -
> Antonio de la Fuente Mart?nez
> E-mail: t...@muybien.org
> -
>
> ___
> Tutor maillist - Tutor@python.org
> To unsubscribe or change subscription options:
> http://mail.python.org/mailman/listinfo/tutor
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[Tutor] Processing rows from CSV
Dear Tutors, A rather general question, I'm afraid. I have found myself writing some python code to handle some CSV data, using the csv. DictReader that generates a dict for each row with the key as the column heading and the value in the file as the item. Most operations involve code of the form: (Apologies for incorrect caps) For row in reader: If row['foo'] == 'something' : do this etc. Typically I'm checking some form of consistency, or adding an element to the row based on something in the row. I know about the existence of awk/ sed etc. Which could do some of this, but I ran into some problems with date manipulation, etc that they don't seem to handle very well. I wanted to ask if anyone knew of anything similar, as I'm worried about re-inventing the wheel. One option would be to use (e.g.) sqlite and then use select/ insert commands, but personally I'd much rather write conditions in python than sql. My other question was about how I do this more efficiently: I don't want to read the whole thing into memory at once, but (AFAIK) csv.DictReader doesn't support something like readline() to deliver it one at a time. Any comments gratefully received. Matt Sent from my BlackBerry® wireless device ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] opening a file directly from memory
Alan Gauld wrote: wrote Yes. My program knows. A database column stores the complete file name (including extension), and I can be certain the applications will be available to run the file. You still haven't answered the question. We have established that a) The OS knows what program is associated with the file b) your program knows the file name and location But does your program - or more specifically you as the author - know what program the OS will use to open the file? Yes. My program knows which program to use (that will be installed). If you do you can call it explicitly, but if you do not then you need to find a way of getting the OS to tell you, or to leave it to the OS. I'm interested in nthis for the sake of generalizing (which is better). How can I get the OS to tell me which program to use. Or alternatively, how to tell the OS to open it - assuming that since the os knows which program to use it will just use it (perhaps too big an assumption ;-) For example a txt file could be opened by any of hundreds of text editors, depending on what the user selected, but a Photoshop file will typically only be opened by photoshop. HTH, Txs, Miguel VIVA os SEUS SONHOS com o Crédito Pessoal Capital Mais. Peça aqui até 15.000 Euros: http://www.iol.pt/correio/rodape.php?dst=0901052 ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Introduction - log exercise
* Wayne Werner [2009-11-17 11:41:25 -0600]: > Date: Tue, 17 Nov 2009 11:41:25 -0600 > From: Wayne Werner > To: Antonio de la Fuente > Cc: Python Tutor mailing list > Subject: Re: [Tutor] Introduction - log exercise > Message-ID: <333efb450911170941g709e7ea3l4b4316044be09...@mail.gmail.com> > > On Tue, Nov 17, 2009 at 10:58 AM, Antonio de la Fuente > wrote: > > > Hi everybody, > > > > This is my first post here. I have started learning python and I am new to > > programing, just some bash scripting, no much. > > Thank you for the kind support and help that you provide in this list. > > > > You're welcome! > > > > > > This is my problem: I've got a log file that is filling up very quickly, > > this > > log file is made of blocks separated by a blank line, inside these blocks > > there > > is a line "foo", I want to discard blocks with that line inside it, and > > create a > > new log file, without those blocks, that will reduce drastically the size > > of the > > log file. > > [...] > > Let me start out by saying this; I'm very impressed with the thought you've > put into the problem and the way you've presented it. > Thank you, it took me some time, but it did help me to understand better the problem. > The first thing that pops into my mind is to simply strip whitespace from > the line and check if the line == ''. Upon further experiment there's the > "isspace" method: > > In [24]: x = ' \n\n\r\t\t' > > In [25]: x.isspace() > Out[25]: True > > x contains a bunch of spaces, newlines, and tab chars. From the docs: > > " Return True if all characters in S are whitespace > and there is at least one character in S, False otherwise." > So, I could use it like this: while not line.isspace() if line == 'foo': Somehow re-initialise myList break [and the rest] > > > > I don't expect the solution, as I think this is a great exercise to get wet > > with python, but if anyone thinks that this is the wrong way of solving the > > problem, please let me know. > > > > for line in fileIn: > >while line != 'blank_line': > >if line == 'foo': > >Somehow re-initialise myList > >break > >else: > >myList.append(line) > >fileOut.writelines(myList) > > > > > Rather than using a while, you can use an if statement with the space method > (and join your statement with an: > > if not line.isspace() and not line == 'foo': > fileOut.write(line) > But then, the new log file will have all the blocks, even the ones that had 'foo' on it, even if the foo lines weren't there anymore. No? or is there anything that I don't get? > then you can get rid of the whole myList. Based on what you've written, > there's really no need to have a list, it's more efficient to just write the > line straight to the file. My idea of using a list was that I can put the block in the list, and if block does not content line with 'foo' then write it to file, otherwise discard block. > > for the renaming part, take a look at the shutil module. > > HTH, > Wayne Thank you Wayne. -- - Antonio de la Fuente Martínez E-mail: t...@muybien.org - Dios mira las manos limpias, no las llenas. -- Publio Siro. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Introduction - log exercise
Antonio de la Fuente wrote:
Hi everybody,
This is my first post here. I have started learning python and I am new to
programing, just some bash scripting, no much.
Thank you for the kind support and help that you provide in this list.
This is my problem: I've got a log file that is filling up very quickly, this
log file is made of blocks separated by a blank line, inside these blocks there
is a line "foo", I want to discard blocks with that line inside it, and create a
new log file, without those blocks, that will reduce drastically the size of the
log file.
The log file is gziped, so I am going to use gzip module, and I am going to pass
the log file as an argument, so sys module is required as well.
I will read lines from file, with the 'for loop', and then I will check them for
'foo' matches with a 'while loop', if matches I (somehow) re-initialise the
list, and if there is no matches for foo, I will append line to the list. When I
get to a blank line (end of block), write myList to an external file. And start
with another line.
I am stuck with defining 'blank line', I don't manage to get throught the while
loop, any hint here I will really appreciate it.
I don't expect the solution, as I think this is a great exercise to get wet
with python, but if anyone thinks that this is the wrong way of solving the
problem, please let me know.
#!/usr/bin/python
import sys
import gzip
myList = []
# At the moment not bother with argument part as I am testing it with a
# testing log file
#fileIn = gzip.open(sys.argv[1])
fileIn = gzip.open('big_log_file.gz', 'r')
fileOut = open('outputFile', 'a')
for line in fileIn:
while line != 'blank_line':
if line == 'foo':
Somehow re-initialise myList
break
else:
myList.append(line)
fileOut.writelines(myList)
Observations:
0 - The other responses did not understand your desire to drop any
paragraph containing 'foo'.
1 - The while loop will run forever, as it keeps processing the same line.
2 - In your sample log file the line with 'foo' starts with a tab. line
== 'foo' will always be false.
3 - Is the first line in the file Tue Nov 17 16:11:47 GMT 2009 or blank?
4 - Is the last line blank?
Better logic:
# open files
paragraph = []
keep = True
for line in fileIn:
if line.isspace(): # end of paragraph
if keep:
outFile.writelines(paragraph)
paragraph = []
keep = True
else:
if keep:
if line == '\tfoo':
keep = False
else:
paragraph.append(line)
# anticipating last line not blank, write last paragraph
if keep:
outFile.writelines(paragraph)
# use shutil to rename
--
Bob Gailer
Chapel Hill NC
919-636-4239
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Re: [Tutor] Introduction - log exercise
On Tue, Nov 17, 2009 at 2:23 PM, Antonio de la Fuente wrote: > But then, the new log file will have all the blocks, even the ones that > had 'foo' on it, even if the foo lines weren't there anymore. No? or > is there anything that I don't get? > Ah yes, I forgot about that part. So you should probably keep the list. -Wayne -- To be considered stupid and to be told so is more painful than being called gluttonous, mendacious, violent, lascivious, lazy, cowardly: every weakness, every vice, has found its defenders, its rhetoric, its ennoblement and exaltation, but stupidity hasn’t. - Primo Levi ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Introduction - log exercise
* Nick Stinemates [2009-11-17 13:30:51 -0500]:
> Date: Tue, 17 Nov 2009 13:30:51 -0500
> From: Nick Stinemates
> To: Antonio de la Fuente
> Cc: Python Tutor mailing list
> Subject: Re: [Tutor] Introduction - log exercise
> Mail-Followup-To: Antonio de la Fuente ,
> Python Tutor mailing list
> User-Agent: Mutt/1.5.20 (2009-06-14)
> Message-ID: <20091117183051.ga20...@stinemates.org>
>
> > I will read lines from file, with the 'for loop', and then I will check
> > them for
> > 'foo' matches with a 'while loop', if matches I (somehow) re-initialise the
> > list, and if there is no matches for foo, I will append line to the list.
> > When I
> > get to a blank line (end of block), write myList to an external file. And
> > start
>
> Can you please explain what you mean by _re-initialize the list_ ?
>
By re-initialize the list I was thinking to get rid of the lines that
have been put into it, until it has been found one with 'foo', if not
it will contaminated the new log file, with lines from blocks that had
'foo' lines.
> > with another line.
> >
> > I am stuck with defining 'blank line', I don't manage to get throught the
> > while
> > loop, any hint here I will really appreciate it.
> > I don't expect the solution, as I think this is a great exercise to get wet
> > with python, but if anyone thinks that this is the wrong way of solving the
> > problem, please let me know.
> >
> >
>
> Can you explain why the following won't work?
>
Because I don't know how to define a blank line, that will allow me to
differentiate between blocks.
>
> #!/usr/bin/python
>
> import sys
> import gzip
> # At the moment not bother with argument part as I am testing it with a
> # testing log file
> #fileIn = gzip.open(sys.argv[1])
>
> fileIn = gzip.open('big_log_file.gz', 'r')
> fileOut = open('outputFile', 'a')
>
> for line in fileIn:
> while line != 'blank_line':
> if 'foo' not in line:
> fileOut.write(line)
[...]
--
-
Antonio de la Fuente Martínez
E-mail: t...@muybien.org
-
El que con niños se acuesta, mojado se levanta.
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Re: [Tutor] Processing rows from CSV
On Tue, Nov 17, 2009 at 1:57 PM, wrote: > A rather general question, I'm afraid. I have found myself writing some > python code to handle some CSV data, using the csv. DictReader that generates > a dict for each row with the key as the column heading and the value in the > file as the item. Most operations involve code of the form: (Apologies for > incorrect caps) > > For row in reader: > If row['foo'] == 'something' : > do this etc. > My other question was about how I do this more efficiently: I don't want to > read the whole thing into memory at once, but (AFAIK) csv.DictReader doesn't > support something like readline() to deliver it one at a time. The loop above does deliver one line worth of data at a time. Kent ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Introduction - log exercise
Antonio de la Fuente wrote:
Hi everybody,
This is my first post here. I have started learning python and I am new to
programing, just some bash scripting, no much.
Thank you for the kind support and help that you provide in this list.
This is my problem: I've got a log file that is filling up very quickly, this
log file is made of blocks separated by a blank line, inside these blocks there
is a line "foo", I want to discard blocks with that line inside it, and create a
new log file, without those blocks, that will reduce drastically the size of the
log file.
The log file is gziped, so I am going to use gzip module, and I am going to pass
the log file as an argument, so sys module is required as well.
I will read lines from file, with the 'for loop', and then I will check them for
'foo' matches with a 'while loop', if matches I (somehow) re-initialise the
list, and if there is no matches for foo, I will append line to the list. When I
get to a blank line (end of block), write myList to an external file. And start
with another line.
I am stuck with defining 'blank line', I don't manage to get throught the while
loop, any hint here I will really appreciate it.
I don't expect the solution, as I think this is a great exercise to get wet
with python, but if anyone thinks that this is the wrong way of solving the
problem, please let me know.
#!/usr/bin/python
import sys
import gzip
myList =]
# At the moment not bother with argument part as I am testing it with a
# testing log file
#fileIn =zip.open(sys.argv[1])
fileIn =zip.open('big_log_file.gz', 'r')
fileOut =pen('outputFile', 'a')
for line in fileIn:
while line !=blank_line':
if line ='foo':
Somehow re-initialise myList
break
else:
myList.append(line)
fileOut.writelines(myList)
Somehow rename outputFile with big_log_file.gz
fileIn.close()
fileOut.close()
-
The log file will be fill with:
Tue Nov 17 16:11:47 GMT 2009
bladi bladi bla
tarila ri la
patatin pataton
tatati tatata
Tue Nov 17 16:12:58 GMT 2009
bladi bladi bla
tarila ri la
patatin pataton
foo
tatati tatata
Tue Nov 17 16:13:42 GMT 2009
bladi bladi bla
tarila ri la
patatin pataton
tatati tatata
etc, etc ,etc
..
Again, thank you.
You've got some good ideas, and I'm going to give you hints, rather than
just writing it for you, as you suggested.
First, let me point out that there are advanced features in Python that
could make a simple program that'd be very hard for a beginner to
understand. I'll give you the words, but recommend that you not try it
at this time. If you were to wrap the file in a generator that returned
you a "paragraph" at a time, the same way as it's now returning a line
at a time, then the loop would be simply a for-loop on that generator,
checking each paragraph for whether it contained "foo" and if so,
writing it to the output.
But you can also do it without using advanced features, and that's what
I'm going to try to outline.
Two things you'll be testing each line for: is it blank, and is it "foo".
if line.isspace() will test if a line is whitespace only, as Wayne
pointed out.
if line == "foo" will test if a line has exactly "foo" in it. But if
you apparently have leading whitespace, and
trailing newlines, and if they're irrelevant, then you might want
if line.strip() == "foo"
I would start by just testing for blank lines. Try replacing all blank
lines with "* blank line " and print each
line. See whether the output makes sense. if it does, go on to the next
step.
for line in
if line-is-blank
line-is-fancy-replacement
print line
Now, instead of just printing the line, add it to a list object. Create
an object called paragraph(rather than a file) as an empty list object,
before the for loop.
Inside the for loop, if the line is non-empty, add it to the paragraph.
If the line is empty, then print the paragraph (with something before
and after it,
so you can see what came from each print stmt). Then blank it (outlist
= []).
Check whether this result looks good, and if so, continue on.
Next version of the code: whenever you have a non-blank line, in
addition to adding it to the list, also check it for whether it's
equal-foo.
If so, set a flag. When printing the outlist, skip the printing if the
flag is set. Remember that you'll have to clear this flag each time you
blank
the mylist, both before the loop, and in the middle of the loop.
Once this makes sense, you can worry about actually writing the output
to a real file, maybe compressing it, maybe doing deletes and renames
as appropriate. You probably don't need shutil module, os module
probably has enough functions for th
Re: [Tutor] Do you use unit testing?
On Mon, Nov 16, 2009 at 3:54 PM, Modulok wrote: > List, > > A general question: > > How many of you guys use unit testing as a development model, or at > all for that matter? > > I just starting messing around with it and it seems painfully slow to > have to write a test for everything you do. Thoughts, experiences, > pros, cons? In my opinion TDD is awesome :-) Why? - It gives you high confidence that your code does what you think it does, and that you can rely on it - It can be a lot of fun to write a test, then make it pass, repeat...each time you make the test pass is a little pat on the back - good work! - It forces you to think as a client of the code that you are writing - It puts pressure on your design, to write code that is - testable (duh) - loosely coupled - reusable (to some extent), because you start with two clients That's just the benefit when you initially write the code. Just as important is the benefit downstream, when you want to make a change. Having a good test suite allows you to make changes to the code (for example refactoring) with confidence that if you break anything, you will find out quickly. This is a profound shift. On projects without tests, there tends to be code whose function is not clear, or whose structure is tangled, which no one wants to touch for fear of breaking something. Generally there is an undercurrent of fear of breakage that promotes code rot. On projects with tests, fear is replaced with confidence. Messes can be cleaned up, dead code stripped out, etc. So tests promote a healthy codebase over time. There is a cost but it is smaller than it looks from the outside. Yes, you have to learn to use a test framework, but that is a one-time cost. I use unittest because it follows the xUnit pattern so it is familiar across Python, Java, C#, etc. There are alternatives such as doctest, nose and py.test that some people prefer. I have written a brief intro to unittest here, with links to comparison articles: http://personalpages.tds.net/~kent37/kk/00014.html You will occasionally have to stop and figure out how to test something new and perhaps write some test scaffolding. That time will pay off hugely as you write tests. You have to write the tests, but what were you doing before? How do you know your code works? You must be doing some kind of tests. If you write your tests as automated unit tests they are preserved and useful in the future, and probably more comprehensive than what you would do by hand. If you test by hand, your tests are lost when you finish. Finally I confess that GUI unit tests are very difficult. I have often omitted them, instead trying to write a thin GUI over a testable layer of functionality. In my current (WinForms, C#) project we have found a workable way to write GUI tests using NUnitForms so in the future maybe I will be writing more GUI unit tests. More advocacy: http://c2.com/cgi/wiki?TestDrivenDevelopment http://c2.com/cgi/wiki?CodeUnitTestFirst Kent ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] opening a file directly from memory
wrote If you do you can call it explicitly, but if you do not then you need to find a way of getting the OS to tell you, or to leave it to the OS. I'm interested in nthis for the sake of generalizing (which is better). How can I get the OS to tell me which program to use. alternatively, how to tell the OS to open it - assuming that since the os knows which program to use it will just use it This is where it gets messy. The solution depends on the OS. If its Windows you can use Startfile. If its MacOS you can interrogate the package manifest. If its another Unix you can use any of several options depending on the flavour. The simplest is, I think, the file command, then if its a text file you can check the shebang line at the top of the file. But modern Unices, like Linux have file association tables - but these are often associated with the desktop environment - KDE, Gnome etc. Finally for text files you should check the EDITOR and VISUAL environment variables - although these are increasingly not used or respected nowadays. So you could write a program that checked the OS and then tried all of these options to identify the host application. But even then you are not guaranteed to succeed! Finally you can try just running the file via os.system or the subprocess module and see what happens! But there is no foolproof way of doing it on all OS. That's why its easier if you either know what app to use or create a config file such that the user can specify the app at install time. On unix that would traditionally be called .myapprc aand be stored in each users home directory. On Windows it would either be a registry entry or a myapp.ini file, usually stored in the Windows directory or (better IMHO but against MS guidelines) in the app directory. HTH, -- Alan Gauld Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] opening a file directly from memory
Dammit. Meant to send this over the list. Sorry, Alan. On Di, 2009-11-17 at 21:33 +, Alan Gauld wrote: > Unices, like Linux have file association tables - but these > are often associated with the desktop environment - KDE, Gnome etc. > Finally for text files you should check the EDITOR and VISUAL > environment variables - although these are increasingly not > used or respected nowadays. I find mimemagic to be quite reliable. File can be silly at times (it routinely diagnoses my python scripts as Java source files). In my gopher server I rely on mimemagic to make an educated guess and only use file(1) as a last resort to find out whether it's a binary file or ASCII text (some gopher clients don't support UTF8). I'm not sure whether mimemagic is also available on other OSes, tho. Cheers Alan ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] opening a file directly from memory
On Tue, Nov 17, 2009 at 1:37 PM, wrote: >> Alan Gauld wrote: >>> >>> wrote >>> If you do you can call it explicitly, but if you do not then you need to >>> find a way of getting the OS to tell you, or to leave it to the OS. > > I'm interested in nthis for the sake of generalizing (which is better). How > can I get the OS to tell me which program to use. Or alternatively, how to > tell the OS to open it - assuming that since the os knows which program to > use it will just use it (perhaps too big an assumption ;-) The "desktop" package provides a portable open() function: http://pypi.python.org/pypi/desktop It came out of this discussion (extensive, with links): http://bugs.python.org/issue1301512 Kent ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Introduction - log exercise
"Antonio de la Fuente" wrote > if not line.isspace() and not line == 'foo': > fileOut.write(line) But then, the new log file will have all the blocks, even the ones that had 'foo' on it, even if the foo lines weren't there anymore. No? or is there anything that I don't get? I think the test should be: if not line.isspace and 'foo' not in line: fileOut.write(line) HTH, -- Alan Gauld Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Introduction - log exercise
* bob gailer [2009-11-17 15:26:20 -0500]:
> Date: Tue, 17 Nov 2009 15:26:20 -0500
> From: bob gailer
> To: Antonio de la Fuente
> CC: Python Tutor mailing list
> Subject: Re: [Tutor] Introduction - log exercise
> User-Agent: Thunderbird 2.0.0.23 (Windows/20090812)
> Message-ID: <4b0306ec.8000...@gmail.com>
>
> Antonio de la Fuente wrote:
> >Hi everybody,
> >
> >This is my first post here. I have started learning python and I am new to
> >programing, just some bash scripting, no much. Thank you for the
> >kind support and help that you provide in this list.
> >
> >This is my problem: I've got a log file that is filling up very quickly, this
> >log file is made of blocks separated by a blank line, inside these blocks
> >there
> >is a line "foo", I want to discard blocks with that line inside it, and
> >create a
> >new log file, without those blocks, that will reduce drastically the size of
> >the
> >log file.
> >
> >The log file is gziped, so I am going to use gzip module, and I am going to
> >pass
> >the log file as an argument, so sys module is required as well.
> >
> >I will read lines from file, with the 'for loop', and then I will check them
> >for
> >'foo' matches with a 'while loop', if matches I (somehow) re-initialise the
> >list, and if there is no matches for foo, I will append line to the list.
> >When I
> >get to a blank line (end of block), write myList to an external file. And
> >start
> >with another line.
> >
> >I am stuck with defining 'blank line', I don't manage to get throught the
> >while
> >loop, any hint here I will really appreciate it.
> >I don't expect the solution, as I think this is a great exercise to get wet
> >with python, but if anyone thinks that this is the wrong way of solving the
> >problem, please let me know.
> >
> >
> >#!/usr/bin/python
> >
> >import sys
> >import gzip
> >
> >myList = []
> >
> ># At the moment not bother with argument part as I am testing it with a
> ># testing log file
> >#fileIn = gzip.open(sys.argv[1])
> >
> >fileIn = gzip.open('big_log_file.gz', 'r')
> >fileOut = open('outputFile', 'a')
> >
> >for line in fileIn:
> >while line != 'blank_line':
> >if line == 'foo':
> >Somehow re-initialise myList
> > break
> >else:
> >myList.append(line)
> >fileOut.writelines(myList)
> Observations:
> 0 - The other responses did not understand your desire to drop any
> paragraph containing 'foo'.
Yes, paragraph == block, that's it
> 1 - The while loop will run forever, as it keeps processing the same line.
Because the tabs in the line with foo?!
> 2 - In your sample log file the line with 'foo' starts with a tab.
> line == 'foo' will always be false.
So I need first to get rid of those tabs, right? I can do that with
line.strip(), but then I need the same formatting for the fileOut.
> 3 - Is the first line in the file Tue Nov 17 16:11:47 GMT 2009 or blank?
First line is Tue Nov 17 16:11:47 GMT 2009
> 4 - Is the last line blank?
last line is blank.
>
> Better logic:
>
I would have never thought this way of solving the problem. Interesting.
> # open files
> paragraph = []
> keep = True
> for line in fileIn:
> if line.isspace(): # end of paragraph
Aha! finding the blank line
>if keep:
> outFile.writelines(paragraph)
>paragraph = []
This is what I called re-initialising the list.
>keep = True
> else:
>if keep:
> if line == '\tfoo':
>keep = False
> else:
>paragraph.append(line)
> # anticipating last line not blank, write last paragraph
> if keep:
> outFile.writelines(paragraph)
>
> # use shutil to rename
>
Thank you.
>
> --
> Bob Gailer
> Chapel Hill NC
> 919-636-4239
--
-
Antonio de la Fuente Martínez
E-mail: t...@muybien.org
-
The problem with people who have no vices is that generally you can
be pretty sure they're going to have some pretty annoying virtues.
-- Elizabeth Taylor
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Re: [Tutor] Introduction - log exercise
* Dave Angel [2009-11-17 16:30:43 -0500]: > Date: Tue, 17 Nov 2009 16:30:43 -0500 > From: Dave Angel > To: Antonio de la Fuente > CC: Python Tutor mailing list > Subject: Re: [Tutor] Introduction - log exercise > User-Agent: Thunderbird 2.0.0.23 (Windows/20090812) > Message-ID: <4b031603.4000...@ieee.org> > > Antonio de la Fuente wrote: > >Hi everybody, > > [...] > >This is my problem: I've got a log file that is filling up very quickly, this > >log file is made of blocks separated by a blank line, inside these blocks > >there > >is a line "foo", I want to discard blocks with that line inside it, and > >create a > >new log file, without those blocks, that will reduce drastically the size of > >the > >log file. > > [...] > You've got some good ideas, and I'm going to give you hints, rather > than just writing it for you, as you suggested. > Much appreciated, really. > First, let me point out that there are advanced features in Python > that could make a simple program that'd be very hard for a beginner > to understand. I'll give you the words, but recommend that you not > try it at this time. If you were to wrap the file in a generator > that returned you a "paragraph" at a time, the same way as it's now > returning a line at a time, then the loop would be simply a for-loop > on that generator, checking each paragraph for whether it contained > "foo" and if so, writing it to the output. > > > But you can also do it without using advanced features, and that's > what I'm going to try to outline. > [...] > Inside the for loop, if the line is non-empty, add it to the > paragraph. If the line is empty, then print the paragraph (with > something before and after it, > so you can see what came from each print stmt). Then blank it > (outlist = []). > Check whether this result looks good, and if so, continue on. for line in fileIn: if line.isspace(): print "* blank line " print myList print "* fancy blank line " myList = [] else: myList.append(line) I think is what i expect, but confuse me that is in this format: ['Tue Nov 17 16:11:47 GMT 2009\n'], '\tbladi bladi bla', '\ttarila ri la\n', '\tpatatin pataton\n', '\ttatati tatata\n', '\tfoo\n'] * fancy blank line * blank line with linefeeds and tabs all over, I see why everybody calls it paragraph. Once I write to a file from the list, it will comeback the initial format of the file? > > Next version of the code: whenever you have a non-blank line, in > addition to adding it to the list, also check it for whether it's > equal-foo. > If so, set a flag. When printing the outlist, skip the printing if > the flag is set. Remember that you'll have to clear this flag each > time you blank > the mylist, both before the loop, and in the middle of the loop. I am a bit lost with the flags, is it what Bob Gailer was calling keep = True, keep = False, right? > > Once this makes sense, you can worry about actually writing the > output to a real file, maybe compressing it, maybe doing deletes and > renames > as appropriate. You probably don't need shutil module, os module > probably has enough functions for this. > > At any of these stages, if you get stuck, call for help. But your > code will be only as complex as that stage needs, so we can find one > bug at a time. > > DaveA > Thank you, it has been very helpful. -- - Antonio de la Fuente Martínez E-mail: t...@muybien.org - Power, like a desolating pestilence, Pollutes whate'er it touches... -- Percy Bysshe Shelley ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Introduction - log exercise
Alan Gauld wrote: "Antonio de la Fuente" wrote > if not line.isspace() and not line == 'foo': > fileOut.write(line) But then, the new log file will have all the blocks, even the ones that had 'foo' on it, even if the foo lines weren't there anymore. No? or is there anything that I don't get? I think the test should be: if not line.isspace and 'foo' not in line: fileOut.write(line) No - that misses the objective of eliminating blocks containing 'foo' -- Bob Gailer Chapel Hill NC 919-636-4239 ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Introduction - log exercise
Antonio de la Fuente wrote:
* bob gailer [2009-11-17 15:26:20 -0500]:
Date: Tue, 17 Nov 2009 15:26:20 -0500
From: bob gailer
To: Antonio de la Fuente
CC: Python Tutor mailing list
Subject: Re: [Tutor] Introduction - log exercise
User-Agent: Thunderbird 2.0.0.23 (Windows/20090812)
Message-ID: <4b0306ec.8000...@gmail.com>
Antonio de la Fuente wrote:
Hi everybody,
This is my first post here. I have started learning python and I am new to
programing, just some bash scripting, no much. Thank you for the
kind support and help that you provide in this list.
This is my problem: I've got a log file that is filling up very quickly, this
log file is made of blocks separated by a blank line, inside these blocks there
is a line "foo", I want to discard blocks with that line inside it, and create a
new log file, without those blocks, that will reduce drastically the size of the
log file.
The log file is gziped, so I am going to use gzip module, and I am going to pass
the log file as an argument, so sys module is required as well.
I will read lines from file, with the 'for loop', and then I will check them for
'foo' matches with a 'while loop', if matches I (somehow) re-initialise the
list, and if there is no matches for foo, I will append line to the list. When I
get to a blank line (end of block), write myList to an external file. And start
with another line.
I am stuck with defining 'blank line', I don't manage to get throught the while
loop, any hint here I will really appreciate it.
I don't expect the solution, as I think this is a great exercise to get wet
with python, but if anyone thinks that this is the wrong way of solving the
problem, please let me know.
#!/usr/bin/python
import sys
import gzip
myList = []
# At the moment not bother with argument part as I am testing it with a
# testing log file
#fileIn = gzip.open(sys.argv[1])
fileIn = gzip.open('big_log_file.gz', 'r')
fileOut = open('outputFile', 'a')
for line in fileIn:
while line != 'blank_line':
if line == 'foo':
Somehow re-initialise myList
break
else:
myList.append(line)
fileOut.writelines(myList)
Observations:
0 - The other responses did not understand your desire to drop any
paragraph containing 'foo'.
Yes, paragraph == block, that's it
1 - The while loop will run forever, as it keeps processing the same line.
Because the tabs in the line with foo?!
No - because within the loop there is nothing reading the next line of
the file!
2 - In your sample log file the line with 'foo' starts with a tab.
line == 'foo' will always be false.
So I need first to get rid of those tabs, right? I can do that with
line.strip(), but then I need the same formatting for the fileOut.
3 - Is the first line in the file Tue Nov 17 16:11:47 GMT 2009 or blank?
First line is Tue Nov 17 16:11:47 GMT 2009
4 - Is the last line blank?
last line is blank.
Better logic:
I would have never thought this way of solving the problem. Interesting.
# open files
paragraph = []
keep = True
for line in fileIn:
if line.isspace(): # end of paragraph
Aha! finding the blank line
if keep:
outFile.writelines(paragraph)
paragraph = []
This is what I called re-initialising the list.
keep = True
else:
if keep:
if line == '\tfoo':
keep = False
else:
paragraph.append(line)
# anticipating last line not blank, write last paragraph
if keep:
outFile.writelines(paragraph)
# use shutil to rename
Thank you.
--
Bob Gailer
Chapel Hill NC
919-636-4239
--
Bob Gailer
Chapel Hill NC
919-636-4239
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Re: [Tutor] Introduction - log exercise
Antonio de la Fuente wrote: * Dave Angel [2009-11-17 16:30:43 -0500]: for line in fileIn: if line.isspace(): print "* blank line " print myList print "* fancy blank line " myList =] else: myList.append(line) I think is what i expect, but confuse me that is in this format: ['Tue Nov 17 16:11:47 GMT 2009\n'], '\tbladi bladi bla', '\ttarila ri la\n', '\tpatatin pataton\n', '\ttatati tatata\n', '\tfoo\n'] * fancy blank line * blank line with linefeeds and tabs all over, I see why everybody calls it paragraph. Once I write to a file from the list, it will comeback the initial format of the file? No, when you want to write it to the file, you'll need to loop through the list. There is a shortcut, however. If you simply do: stdout.write( "".join(myList) ) it will join all the strings in the list together into one big string and then send it to stdout. You can do that because each line still has its newline at the end. BTW, the list you quoted above is malformed. You really need to copy&paste code and data into the message, so information isn't lost. You have an extra right bracket and a missing \n in there. Next version of the code: whenever you have a non-blank line, in addition to adding it to the list, also check it for whether it's equal-foo. If so, set a flag. When printing the outlist, skip the printing if the flag is set. Remember that you'll have to clear this flag each time you blank the mylist, both before the loop, and in the middle of the loop. I am a bit lost with the flags, is it what Bob Gailer was calling keep True, keep = False, right? You can certainly call it 'keep' The point is, it'll tell you whether to output a particular paragraph or not. Once this makes sense, you can worry about actually writing the output to a real file, maybe compressing it, maybe doing deletes and renames as appropriate. You probably don't need shutil module, os module probably has enough functions for this. At any of these stages, if you get stuck, call for help. But your code will be only as complex as that stage needs, so we can find one bug at a time. DaveA Thank you, it has been very helpful. You're very welcome. DaveA ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] proxy switcher - was Re: I love python / you guys :)
Hi guys! Thank you all for the brainstorming. As much as i love to follow all your tips but sorry I got lost in the sea of discussion :-) Therefore i thought i start to roll out my own and i hope you guys can chime in. The print lines in my code are just for debugging. Of course they can be omitted but for a newbie like me I helps to see what I'm doing is what I'm expected to do. I would like to improve my line search with the module re but cant find something to get me started. I appreciate if you can show me how. The 'proxy' search works but I'm sure with re module the search will be definite i mean wont yield 'false positive' result, sort-of. http://pastebin.ca/1675865 -- Best Regards, bibimidi Sent from Dhahran, 04, Saudi Arabia ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
