Re: [Tutor] Variables and constants [was Re: working with strings inpython3]
And presumably cleans up the leftover object with the value of 42 when it changes to point at the 43 object? Or does it leave all changes in memory until the program exits? Bodsda. Sorry for top posting, my phone won't let me change it Sent from my BlackBerry® wireless device -Original Message- From: Steven D'Aprano Sender: tutor-bounces+bodsda=ubuntu@python.org Date: Wed, 20 Apr 2011 04:24:03 To: tutor Subject: [Tutor] Variables and constants [was Re: working with strings in python3] Rance Hall wrote: > Variables are variable, that's why we call them variable. > Constants are constant, and that's why we call them constant. And Python has neither variables nor constants in the sense that (say) Pascal, C or Fortran have, even though we often use the same words. The differences are quite deep, but they're also subtle. In classic programming languages with variables and/or constants, the model is that names like "x" refer to *memory locations*. If the name is a variable, the compiler will allow you to mutate the value stored at that memory location; if the name is a constant, it won't. But once a name "x" is associated with memory location (say) 123456, it can never move. But note that the "variability" or "constantness" is associated with the *name* (the memory location), not the value. In languages like Python, names are associated with values, without reference to memory locations. In this case, the "variability" or "constantness" is associated with the *value*, not the name. Consider x = 42; x = x+1. In Pascal, C or Fortran, this will actually change a block of memory that had the value 42 into 43 instead: The name x points to a memory location with value 42. Leave the name pointing to the same place, but change the value to 43 instead. In Python, the situation is different: The name x points to an object with value 42. Leave the object 42 alone, but change the name x to point to an object with value 43 instead. -- Steven ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] Gtk - relational data display and edit
Hi, I am reading in data from a csv file which will be in a format like this User1, attrib1, attrib2 User2, attrib1, attrib2 Etc. And need to display this in a window. My initial thought was to use gtk.Entry widgets because I will need to edit this data, but I don't think this will work as I will also need to read the data back, in relation to the user column, e.g I will have something like [Psuedocode] For I in entries: A = usercolumn B = attrib1column C = attrib2column Somefunction(A,B,C) [/psuedocode] I don't think I could use this method with entry boxes as I have no idea how many entries there will be (column length will be fixed) so I can't create the entry widgets beforehand Anyone have any suggestions? Thanks, Bodsda 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] Gtk - relational data display and edit
Thanks for your reply. Unfortunately I can't change the data format because it is output from a closed source app. I can't figure out a way to create the entry widgets on the fly because they need to be bound to a variable to attach them to a gtk.Table and to be able to read the data from them Bodsda Sent from my BlackBerry® wireless device -Original Message- From: Walter Prins Date: Tue, 26 Apr 2011 16:55:36 To: Cc: Subject: Re: [Tutor] Gtk - relational data display and edit On 26 April 2011 16:34, wrote: > Hi, > > I am reading in data from a csv file which will be in a format like this > > User1, attrib1, attrib2 > User2, attrib1, attrib2 > Etc. > Why would the data be in this format? Are you defining it? Reason I ask is that, relationally speaking, (e.g. database design-wise) this is a denormalised representation and you'd do better to store a single attribute per record. E.g. have entities, User, Attrib, and have relationship table User_Attrib that contains only user, attrib pairs. But, maybe such ideas are overkill for your app. > And need to display this in a window. My initial thought was to use > gtk.Entry widgets because I will need to edit this data, but I don't think > this will work as I will also need to read the data back, in relation to the > user column, e.g I will have something like > > [Psuedocode] > For I in entries: >A = usercolumn >B = attrib1column >C = attrib2column > >Somefunction(A,B,C) > [/psuedocode] > > I don't think I could use this method with entry boxes as I have no idea > how many entries there will be (column length will be fixed) so I can't > create the entry widgets beforehand > > Anyone have any suggestions? > Well if you can count the number of entries on reading the file (whatever the shape of the file) then in principle you can dynamically create the correct number of entry boxes on the fly. Of course, if you store one attribe per record, then counting the number of attributes (records) for a given user becomes quite easy of course. But even if you don't do this, and you have the file structure you described, you can code reader code that would internally store the attributes and the number of attributes for each user, enabling you to write code to create the UI with the appropriate number of entry widgets. Walter ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Python program with multiple answers
Hi,
I would suggest appending the dice[roll] to a new list just after the print
statement, then in the quit block order the list and then loop over it and
print each entry.
Hope this helps,
Bodsda
Sent from my BlackBerry® wireless device
-Original Message-
From: Johnson Tran
Sender: tutor-bounces+bodsda=ubuntu@python.org
Date: Wed, 11 May 2011 03:49:12
To:
Subject: [Tutor] Python program with multiple answers
Hi Guys,
I've been working on a Python program where I create an 8 ball that will allow
you to ask questions and will reply back with 20 possible answers. It will be
continuous until the user says quit. My program works fine although I am trying
to add something more to it, where when the user quits, it will present all the
answers that the user got again and display them in alphabetical order...if
anyone could point me in the right direction it'd be really helpful...my
program so far is : (which works fine with no errros)
import random
dice = ("Without a doubt", "It is certain", "It is decidedly so","Yes", "For
Sure", "No", "Dont count on it", "Try asking again","Reply hazy, try again",
"Confucious says 'No'", "Better not tell you now","Cannot predict
now","Concentrate and ask again","My reply is no","Outlook not so good","Very
doubtful","Outlook is good","Most likely","As I see it, yes","I do not
understand the question")
while True:
choice = raw_input("Type 'ask' to ask a question. Type 'quit' to
quit.\n")
if choice == "ask":
raw_input("Please enter your question:\n")
roll = random.randint(0, 10)
print dice[roll]
raw_input()
elif choice == "quit":
True = 0
raw_input()
else:
print "Error -- Try again\n"
Thanks,
JT
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Re: [Tutor] how to sort the file out
I'm also slightly confused. Why does file one start at 1, but file 2 starts at 3. Why not just duplicate file2? Bodsda Sent from my BlackBerry® wireless device -Original Message- From: lina Sender: tutor-bounces+bodsda=googlemail@python.org Date: Wed, 7 Sep 2011 12:46:37 To: tutor Subject: [Tutor] how to sort the file out HI, I have two files, one is reference file, another is waiting for adjust one, File 1: 1 C1 2 O1 3 C2 4 C3 5 H3 6 C7 7 O2 8 H22 9 C6 10 H61 11 C5 12 H5 13 C4 14 C8 15 C9 16 C10 17 O3 18 C11 19 C12 20 O4 21 C13 22 C14 23 C15 24 C20 25 H20 26 C16 27 H16 28 C17 29 H17 30 C18 31 O6 32 H62 33 C19 34 O5 35 C21 File 2: 3 H16 4 H5 6 H61 7 H17 9 H20 12 H3 13 C1 14 O1 15 C2 16 C3 17 C4 18 C5 19 C6 20 C7 21 C8 22 C9 23 C10 24 O3 25 C11 26 C12 27 O4 28 C13 29 C14 30 C15 31 C20 32 C19 33 C18 34 C17 35 C16 36 O5 37 C21 38 O6 39 H62 40 O2 41 H22 I wish the field 2 from file 2 arranged the same sequence as the field 2 of file 1. Thanks for any suggestions, I drove my minds into nuts already, three hours passed and I still failed to achieve this. -- Best Regards, lina ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] If statement optimization
Hi, In a normal if,elif,elif,...,else statement, are the conditions checked in a linear fashion? I am wondering if I should be making an effort to put the most likely true condition at the beginning of the block Thanks, Bodsda 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] If statement optimization
Thanks for the explanation - very clear.
Cheers,
Bodsda
Sent from my BlackBerry® wireless device
-Original Message-
From: Steven D'Aprano
Sender: tutor-bounces+bodsda=googlemail@python.org
Date: Fri, 16 Sep 2011 20:43:45
To: Tutor - python List
Subject: Re: [Tutor] If statement optimization
bod...@googlemail.com wrote:
> Hi,
>
> In a normal if,elif,elif,...,else statement, are the conditions checked in a
> linear fashion?
Yes.
> I am wondering if I should be making an effort to put the most likely true
> condition at the beginning of the block
Probably not. The amount of time used in the average if...elif is
unlikely to be significant itself. Don't waste your time trying to
optimize something like this:
if n < 0:
...
elif n == 0:
...
else:
...
However, there are exceptions.
If the tests are very expensive, then it might be worthwhile putting the
most likely case first. Or at least, put the cheapest cases first, leave
the expensive ones for last:
if sum(mylist[1:]) > 1000 and mylist.count(42) == 3 and min(mylist) < 0:
...
elif len(mylist) < 5:
...
I probably should swap the order there, get the cheap len() test out of
the way, and only perform the expensive test if that fails.
If you have LOTS of elif cases, like *dozens*, then firstly you should
think very hard about re-writing your code, because that's pretty poor
design... but if you can't change the design, then maybe it is
worthwhile to rearrange the cases.
If you have something like this:
if s == "spam":
func_spam(x)
elif s == "ham":
func_ham(x)
elif s == "cheese":
func_cheese(x)
you can often turn this into a dispatch table:
table = {"spam": func_spam, "ham": func_ham, "cheese": func_cheese}
func = table[s] # lookup in the dispatch table
func(x) # finally call the function
Note that inside table, you don't call the functions.
This pattern is especially useful, as lookup in a table in this manner
takes close enough to constant time, whether there is one item or a million.
--
Steven
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Re: [Tutor] string formatting
Is there any additional overhead of using the locals() or format(locals()) instead of a tuple? - the format option is a double function call so I would expect that to be considerably slower Thanks, Bodsda -- my phone won't let me bottom post, sorry Sent from my BlackBerry® wireless device -Original Message- From: Wayne Werner Sender: tutor-bounces+bodsda=googlemail@python.org Date: Mon, 19 Sep 2011 12:47:01 To: Pirritano, Matthew Cc: Subject: Re: [Tutor] string formatting ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] paper scissors
The %s signifies that a string will be provided to go there. The % after the string signifies that the following variable/strings/tuple will contain the items to be placed where the %s's are (in order) The tuple (wins, losses) are the two items that should replace the %s's Be aware that there are other place holders such as %i and %d that expect a certain data type. With %s, if it is not a string that is given to it, it will attempt to be converted to a string first. Hope this helps, Bodsda Sent from my BlackBerry® wireless device -Original Message- From: bob gailer Sender: tutor-bounces+bodsda=googlemail@python.org Date: Fri, 23 Sep 2011 15:02:44 To: *tutor python Subject: Re: [Tutor] paper scissors ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] where to look for python codes
I would suggest looking on http://ubuntuforums.org for the “Beginner programming challenges“ - there is an index of past challenges as a sticky in the programming talk subforum. A large number of entries for these challenges are in python, and as the name implies, the submissions are usually written by beginners. The code will not be enterprise standard, but it should be a good insight into how others write python programs Hope this helps, Bodsda, Ubuntu beginners team P.S: sorry for the top post, smartphone limitation Sent from my BlackBerry® wireless device -Original Message- From: Praveen Singh Sender: tutor-bounces+bodsda=googlemail@python.org Date: Thu, 29 Sep 2011 13:57:46 To: Subject: [Tutor] where to look for python codes ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] guess age programme (please help)
Hi, I haven't checked your code because I am on my phone, but here is a tip for the loop condition Use the guess in your loop condition e.g. while guesses != 0: Do stuff That way, when guesses does equal 0, the loop condition will be false and therefore the loop will not run. If you don't want to do that, look into the 'break' statement. while someOtherCondition: Do stuff if guesses == 0: break Hope this helps, Bodsda Sent from my BlackBerry® wireless device -Original Message- From: ADRIAN KELLY Sender: tutor-bounces+bodsda=googlemail@python.org Date: Fri, 30 Sep 2011 12:04:58 To: Subject: [Tutor] guess age programme (please help) ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] guess age programme (still stuck!!!!!)
If I enter 35 at the prompt in your program, does python see this: 35 Or this: “35“ ? Hope this helps, Bodsda Sent from my BlackBerry® wireless device -Original Message- From: ADRIAN KELLY Sender: tutor-bounces+bodsda=googlemail@python.org Date: Fri, 30 Sep 2011 19:18:15 To: Cc: Subject: Re: [Tutor] guess age programme (still stuck!) ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Input
You could also use something like pygame to wait and test for keypresses Bodsda (Top post is phone limitation, sorry) Sent from my BlackBerry® wireless device -Original Message- From: Mark Lybrand Sender: tutor-bounces+bodsda=googlemail@python.org Date: Fri, 30 Sep 2011 13:27:27 To: Cc: Subject: Re: [Tutor] Input ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Calling Python Functions from Powershell scripts
You can run .py files from powershell, just like you would run any other command - 'python myfile.py' I don't have any experience of the logging modules, but what I do when using multiple languages is have them all write to the same plain text log file and just prepend [] to the beginning of each line - that way I can track execution order and follow error/info messages all in one file. That's just how I prefer to do it. Bodsda Sent from my BlackBerry® wireless device -Original Message- From: Nikunj Badjatya Sender: tutor-bounces+bodsda=googlemail@python.org Date: Wed, 5 Oct 2011 13:02:23 To: tutor Subject: [Tutor] Calling Python Functions from Powershell scripts ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Python Job Scheduling package
Have you thought about writing your own? Others have posted some useful links, but in all honesty you could hack something together to achieve that in next to no time Bodsda Sent from my BlackBerry® wireless device -Original Message- From: harish bansal Sender: tutor-bounces+bodsda=googlemail@python.org Date: Thu, 13 Oct 2011 15:23:04 To: Subject: [Tutor] Python Job Scheduling package ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] printing a key not a value
Sure,
mydict = {'a':1, 'b',2}
for key in mydict:
print key
Hope this helps,
Bodsda
Sent from my BlackBerry® wireless device
-Original Message-
From: ADRIAN KELLY
Sender: tutor-bounces+bodsda=googlemail@python.org
Date: Tue, 25 Oct 2011 13:45:50
To:
Subject: [Tutor] printing a key not a value
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Re: [Tutor] how can I save it from "for"
Look into the 'continue' and 'break' statements - both very handy when working
with loops
Or just increment/decrement the conditional until it evaluates to False
Bodsda
Sent from my BlackBerry® wireless device
-Original Message-
From: lina
Sender: tutor-bounces+bodsda=googlemail@python.org
Date: Sat, 12 Nov 2011 00:41:43
To: tutor
Subject: [Tutor] how can I save it from "for"
Hi, I don't know how to escape the
if longest >= 3:
subgroup=S1[x_longest-longest:x_longest]
print(subgroup)
form the loop.
xrange = range
subgroup=[]
def LongestCommonSubstring(S1, S2):
M = [[0]*(1+len(S2)) for i in xrange(1+len(S1))]
longest, x_longest = 0, 0
subgroups=[]
uniq={}
for x in xrange(1,1+len(S1)):
for y in xrange(1,1+len(S2)):
if S1[x-1] == S2[y-1]:
M[x][y] = M[x-1][y-1]+1
if M[x][y] > longest:
longest = M[x][y]
x_longest = x
else:
M[x][y] = 0
if longest >= 3:
subgroup=S1[x_longest-longest:x_longest]
print(subgroup)
return S1[x_longest-longest:x_longest]
if __name__=="__main__":
for i in range(97,107):
for j in range(97,107):
if i != j:
LongestCommonSubstring(a,b)
'''LongestCommonSubstring(chr(i),chr(j))'''
Thanks ahead,
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Re: [Tutor] Help with error in ski game
Just a guess but take a look at the spelling. centerx Or centrex Bodsda Sent from my BlackBerry® wireless device -Original Message- From: Chloe Beck Sender: tutor-bounces+bodsda=googlemail@python.org Date: Sun, 20 Nov 2011 11:58:25 To: Subject: [Tutor] Help with error in ski game ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] ProgressBar - Python and Powershell
This is just my opinion but I would have several (say 10) powershell scripts individually called by python, python will sit still until the powershell exits, then update the progress bar by 10% before calling the next script etc etc. Bodsda Sent from my BlackBerry® wireless device -Original Message- From: Sender: tutor-bounces+bodsda=googlemail@python.org Date: Sun, 20 Nov 2011 08:00:43 To: ; Subject: Re: [Tutor] ProgressBar - Python and Powershell ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Making a function run every second.
You won't get it exactly on because the time it takes to call the function will
affect your trigger time.
I would use something like an infinite loop with a 1 second sleep after the
function call
Bodsda
Sent from my BlackBerry® wireless device
-Original Message-
From: "Mic"
Sender: tutor-bounces+bodsda=googlemail@python.org
Date: Tue, 29 Nov 2011 15:54:59
To:
Subject: [Tutor] Making a function run every second.
Hi
I want a function to run every second , how do I do that?
Say that the function look like this:
def hi():
print("hi")
Thanks!
Mic
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Re: [Tutor] How to write lines in a text file (GUI)
Hi,
This is a very simple objective to achieve, so instead of giving you a straight
up solution, I will just nudge your train of thought in the right direction.
Note: I'm struggling to follow your code whilst reading on my phone so the
following suggestions make no reference to your particular codebase
Let's first assume that all buttons could be pressed in any order, therefore
given the following presses: but1, but2, but2, but3, we will have the first
line with hi_1, the second line empty and the third line hi_3. Now I also
assume that there is no 'update file' button, therefore each press of a button
needs to update the file making a change to a single line. That sounds to me
like a good use for an update_file function that accepts a parameter of which
line should be updated. So the main challenge is to write a function that can
read/write to a file certain data depending on the argument passed. The
function should:
Read file
Identify line to be changed
If line empty
Change line to hi_#
Write file
When you open a file, you could then use the read function to read the whole
file, or you could use the readlines function to read the file line by line.
Experiment with both, see what data types they both return and decide which is
most suitable. Bear in mind you need to easily differentiate each line and
access them individually.
If your still struggling to write this function, show us how far you get and we
can go from there.
Hope this helps,
Bodsda
Sent from my BlackBerry® wireless device
-Original Message-
From: "Mic"
Sender: tutor-bounces+bodsda=googlemail@python.org
Date: Tue, 29 Nov 2011 19:02:52
To:
Subject: [Tutor] How to write lines in a text file (GUI)
Hey again.
I figured I would first post this piece of code and then ask my questions.
FREE = "green"
OCCUPIED = "red"
class Mainwindow(Frame):
def __init__(self,master):
super(Mainwindow,self).__init__(master)
self.grid()
self.create_mainwidgets()
def create_mainwidgets(self):
self.klicka=Button(self, text="Press the button",
command=self.uppdatera)
self.klicka.grid()
def uppdatera(self):
SeatWindow(root)
class SeatButton(tk.Button):
def __init__(self, master, index):
text = str(index+1)
super(SeatButton, self).__init__(master,
text=text, bg=FREE,
command=self.clicked)
self.filename = "Germany_France{}.txt".format(index+1)
self.occupied = False
if os.path.exists(self.filename):
self["bg"]=OCCUPIED
def clicked(self):
self.occupied = not self.occupied
if self.occupied:
self["bg"] = OCCUPIED
text_file=open(self.filename,"w")
text_file.write(self.filename)
text_file.close()
else:
self["bg"] = FREE
os.remove(self.filename)
class SeatWindow(tk.Toplevel):
def __init__(self, master):
super (SeatWindow, self).__init__(master)
self.grid()
self.create_widgets()
def create_widgets(self):
for index in range(20):
button = SeatButton(self, index)
row, column = divmod(index, 4)
button.grid(row=row, column=column)
root=Tk()
root.title("testV2")
app=Mainwindow(root)
root.mainloop()
I am now writing another program. It turned out just fine, but I have one
question.
If button one is pressed I want the program to write, say hi_1, on the first
line in a text file.
If button one is pressed again, the first line should be empty.
If button two is pressed I want the program to write hi_2 in the second line
in the text file.
If button two is pressed again, the second line in the text file should be
empty.
If button three is pressed I want the program to write hi_3 in the third
line in the text file.
if button three is pressed again, the third line in the text file should be
empty.
There shouldn't be any other changes to the program other than this above.
There is already a text file
created, the program doesn't need to create one. We can call that file "Hi".
I hope you understand what I want to do here. I have tried the entire
evening yesterday to get this to work, I tried using writeline() but I can't
get it to work.
What are your suggestions to this?
Thank you for your help and time!
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Re: [Tutor] How to write lines in a text file (GUI)
I'm not sure, I also don't have access to the python docs atm, but the simplest method would be to read the whole file into a list, edit the correct item (remembering to count from 0 not 1) and then writing the whole list back to the file. Bodsda --Original Message-- From: Mic To: bod...@googlemail.com To: tutor-bounces+bodsda=googlemail@python.org To: Tutor - python List Subject: Re: [Tutor] How to write lines in a text file (GUI) Sent: 29 Nov 2011 19:24 >Note: I'm struggling to follow your code whilst reading on my phone so the >following suggestions make no reference to your particular codebase Okay I understand. Perhaps it doesn't matter. >Let's first assume that all buttons could be pressed in any order, >therefore given the following presses: but1, but2, but2, but3, we will have >the first line with hi_1, the second line empty and the third line hi_3. >Now I also assume that there >is no 'update file' button, therefore each >press of a button needs to update the file making a change to a single >line. That sounds to me like a good use for an update_file function that >accepts a parameter of which line should be updated. >So the main challenge >is to write a function that can read/write to a file certain data depending >on the argument passed. The function should: >Read file >Identify line to be changed >If line empty >Change line to hi_# >Write file >When you open a file, you could then use the read function to read the >whole file, or you could use the readlines function to read the file line >by line. Experiment with both, see what data types they both return and >decide which is most >suitable. Bear in mind you need to easily >differentiate each line and access them individually. >If your still struggling to write this function, show us how far you get >and we can go from there. Actually, I nearly know how do to solve this problem. I just have one problem. Can I use writeline() to write text into line 3 or line 5 for example? Say that I want to write the text "hi" into line five of a text file, can I do this using writeline(), if so, how ? Thanks for the response! Hope this helps, Bodsda Sent from my BlackBerry® wireless device 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] list, tuple or dictionary
You could use any of them, but a dict would be the most logical assuming no duplicate items Bodsda Sent from my BlackBerry® wireless device -Original Message- From: ADRIAN KELLY Sender: tutor-bounces+bodsda=googlemail@python.org Date: Tue, 29 Nov 2011 20:31:56 To: Subject: [Tutor] list, tuple or dictionary ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Python Saved the Day
We had a challenge recently where all of our internal department names changed, and due to our intranet system, we had to modify our Active Directory to reflect the new names. This meant changing all usernames, public drives and pc names. We were also migrating the profiles from one profile server to another at the same time. A manual test run of our procedure determined a 6 hour process per depart. Worried for the strain this would have on my sanity, I spent 3 hours automating this process in python, cutting the execution time down to 30 minutes of watching success messages printing to the screen. This saved an estimated 55 man hours of work. Bodsda Sent from my BlackBerry® wireless device -Original Message- From: wesley chun Sender: tutor-bounces+bodsda=googlemail@python.org Date: Sun, 4 Dec 2011 00:51:59 To: Mark Lybrand Cc: Subject: Re: [Tutor] Python Saved the Day ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] unable to run file though dir path included
This is only a guess, but when your typing 'python foo.py' the command prompt is looking for foo.py in its path and can't find it, then it throws the error. When your in the interpreter, python has already updated its path so it can find your file. I don't think adding the directory to 'python\Lib\Site-packages' is doing what you think it should do. Bodsda Sent from my BlackBerry® wireless device -Original Message- From: surya k Sender: tutor-bounces+bodsda=googlemail@python.org Date: Wed, 7 Dec 2011 00:27:30 To: Python Tutor Subject: [Tutor] unable to run file though dir path included ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Interprocess communication
If you invoke the system 'cp' command though, it may not be possible to have a progress bar because the command will only talk back when it exits. Bodsda Sent from my BlackBerry® wireless device -Original Message- From: Alan Gauld Sender: tutor-bounces+bodsda=googlemail@python.org Date: Tue, 06 Dec 2011 19:04:01 To: Subject: Re: [Tutor] Interprocess communication On 06/12/11 17:17, George Nyoro wrote: > Hey guys, >Really want to thank all of you for helping and bearing with > some of us and the questions we ask around here. I was making a gtk > app sometime ago to copy files from a cd or dvd to my hard disk since > the normal ubuntu copy thing would stop when it encountered some > error, so I needed one that read through errors or none. For me the normal copy thing is the cp command. It reads through errors quite happily... I assume you mean one of the graphical file managers abailable in Ubuntu? > I did in two modules: one having gtk code and the other having the > copy code, then id import the copy code into gtk. The thing is that > when the gtk called the copy module to do so, the process would take > long and so the application would become none responsive. How are you doing the copy? If its a long loop or using os.walk() then you need to put it in a separate thread. Thats probably the best solution. Alternartively invoke the cp command line and run it in the background(with &), but then you won;t get suvch good error reports etc... Otherwise break it into chunks so you only copy a few files at a time and then return to the GUI. But that will slow the copy process even more! > Can anyone show me how to run the gtk and copy code as separate > processes since this seems to be the only way that the application > graphics wont hang? Thanks in advance. You don't need separate processes just separate threads. Check the Python documentation for a threading tutorial. -- Alan G 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 ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] how to find index of list with its value
>>>mylist = [1,2,3,4,1] >>>mylist.index(1) 0 But note that this only shows the index for the first occurrence of the item. Bodsda Sent from my BlackBerry® wireless device -Original Message- From: surya k Sender: tutor-bounces+bodsda=googlemail@python.org Date: Thu, 8 Dec 2011 20:58:37 To: Python Tutor Subject: [Tutor] how to find index of list with its value Well, we all know to know the value when we have the index of a list. But how can we find it in the reverse way... say a listl=[1,2,3,4] l[0]=1.but how can I find its address with its value 1 ?? ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] list.index() question
That won't work because l1[0] is ['a', 1]
What happens if you don't change the code?
l1.index('c')
Bodsda
Sent from my BlackBerry® wireless device
-Original Message-
From: Robert Berman
Sender: tutor-bounces+bodsda=googlemail@python.org
Date: Thu, 08 Dec 2011 16:13:32
To: tutor
Subject: [Tutor] list.index() question
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Re: [Tutor] return, why do I need it?
Why unindent functions for testing? Challenge: write a function called myadd(one, two) that accepts 2 parameters, both will be ints. When the function is called, it should add both parameters together. It should allow me to do this: a = myadd(5, 10) a += myadd(10, 5) a == 30 True Hopefully that shows one usage of return values Hth, Bodsda Sent from my BlackBerry® wireless device -Original Message- From: "Pete O'Connell" Sender: tutor-bounces+bodsda=googlemail@python.org Date: Mon, 12 Dec 2011 01:08:47 To: Subject: [Tutor] return, why do I need it? ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] unsupported operand
I would suggest a few things, like variable naming style consistency or the
unused file that you open and close. You also have an unused lw variable, and
does dpi really need to be a variable? Its only used once, why not hard code it.
But the main thing I suggest, is posting the 'complete' traceback, so we can
see what caused the error. I'm gonna take a wild guess at it being the
pyplot.plot call though, due to the data types that its moaning about.
Bodsda
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-Original Message-
From: stm atoc
Sender: tutor-bounces+bodsda=googlemail@python.org
Date: Sat, 17 Dec 2011 21:30:17
To: tutor
Subject: [Tutor] unsupported operand
Hi there,
I would like to define concentration array based on time and then plot it.
Here is the profile:
from pylab import *
import numpy
import array
import math
tmax=1*3600
t = 1.
outfile=open('ourtest_out.list','w')
N = 100
Conc1 = arange([0, tmax])
outfile.close()
lw = 2.0 #linewidth
dpi = 96
figure(figsize=(12,6),dpi=dpi)
pyplot.plot(Conc1, t,'r-',label='Conc' )
savefig('Conc.png')
show()
and this is the error that I got:
TypeError: unsupported operand type(s) for -: 'list' and 'int'
What would you suggest?
Thank you,
Sue
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Re: [Tutor] A few Python Mysteries
I think your missing the point. Ignore the fact that your PATH doesn't contain the correct paths to python. The problem is that on startup, a program (unknown) is looking for the dll file for python2.5 - it is looking for this in the system32 directory. To be rid of the startup errors, you need to replace the dll that was removed by the uninstallation of python2.5 - to do this, reinstall python2.5 Bodsda Sent from my BlackBerry® wireless device -Original Message- From: Wayne Watson Sender: tutor-bounces+bodsda=googlemail@python.org Date: Wed, 21 Dec 2011 07:15:31 To: Steven D'Aprano; tutor@python.org Subject: Re: [Tutor] A few Python Mysteries Python is long gone from my system. I only have Python 27. Somewhere a long the line, the uninstall of Python5 probably did not remove the Python5 from the PATH. I have no explanation as to why Python7 was not in the PATH. I have no idea why some remnant of why Python6 is hanging around. I uninstalled it long ago too. On 12/21/2011 2:43 AM, Steven D'Aprano wrote: > Wayne Watson wrote: >> I changed Python25 to Python27, and rebooted. I got the same two dll >> msgs again. > > I suggest you find out what applications are trying to run using > Python 2.5. This is a Windows problem -- you need to get the list of > programs that run at start up and inspect them for something that uses > Python. > > Since I don't use Windows, I can't be more specific. > > > -- Wayne Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet CE 1955 October 20 07:53:32.6 UT -- "The Date" The mystery unfolds. Web Page: ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] re module help
You could use read directly on the popen call to negate having to write to a file output = os.popen(“sdptool -i hci0 search OPUSH“).read() Bodsda Sent from my BlackBerry® wireless device -Original Message- From: Ganesh Kumar Sender: tutor-bounces+bodsda=googlemail@python.org Date: Mon, 9 Jan 2012 14:47:46 To: Subject: [Tutor] re module help ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] help with program from learning python the hard way
If I say that sys.argv is a list, does that help you? Also, run things from a command prompt for this kind of thing, at least then you can guarantee what args get passed Bodsda Sent from my BlackBerry® wireless device -Original Message- From: Jason Loeve Sender: tutor-bounces+bodsda=googlemail@python.org Date: Thu, 19 Jan 2012 15:02:41 To: Subject: [Tutor] help with program from learning python the hard way ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
