[Tutor] what does the "@" operator mean?
> From: "Alan Gauld" > Subject: Re: [Tutor] what does the "@" operator mean? Thinking it's quite funny, I'll keep on with italian words: the @ is called "chiocciola" which means snail, while # is called "cancelletto" which is a small gate As you see italian words are quite close to the sign shape, like in Denmark i guess (trunk-a for @ is fantastic! :-P ) ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] sys.path.append
I can do this : >>> sys.path.append ( 'C:\dump1' ) but not : >>> x = 'C:\dir1' >>> sys.path.append(x) or : but not : >>> x = ['C:\dir1'] >>> sys.path.append(x) Can I append variables to the path, rather than explicit strings ? -- View this message in context: http://www.nabble.com/sys.path.append-tp21054555p21054555.html Sent from the Python - tutor mailing list archive at Nabble.com. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] sys.path.append
On Wed, Dec 17, 2008 at 10:20 AM, ppaarrkk wrote: > > I can do this : > sys.path.append ( 'C:\dump1' ) Note you should use raw strings r'C:\dump1' or double backslash 'C:\\dump1' because the \ is a string escape character. > but not : > x = 'C:\dir1' sys.path.append(x) That should work fine (other than the single \). What happens when you try it? > or : ?? > but not : x = ['C:\dir1'] sys.path.append(x) Here you are appending a list of strings to sys.path, that will not do what you want. > Can I append variables to the path, rather than explicit strings ? Sure. Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Lucky Boy Sudhir wants to chat
Thank you Tom -Original Message- From: Kent Johnson [mailto:ken...@tds.net] Sent: Wednesday, December 17, 2008 6:52 AM To: Lucky Boy Sudhir Cc: tutor@python.org Subject: Re: [Tutor] Lucky Boy Sudhir wants to chat I have unsubscribed Lucky Boy from the list as he is just spamming it. Kent On Wed, Dec 17, 2008 at 7:01 AM, Lucky Boy Sudhir wrote: > --- > > Lucky Boy Sudhir wants to stay in better touch using some of Google's > coolest new > products. > > If you already have Gmail or Google Talk, visit: > http://mail.google.com/mail/b-4696b4693-d5d69810df-aafd3a6b94976b5f > You'll need to click this link to be able to chat with Lucky Boy Sudhir . > > To get Gmail - a free email account from Google with over 2,800 megabytes of > storage - and chat with Lucky Boy Sudhir , visit: > http://mail.google.com/mail/a-4696b4693-d5d69810df-ee3cdf55e5 > > Gmail offers: > - Instant messaging right inside Gmail > - Powerful spam protection > - Built-in search for finding your messages and a helpful way of organizing > emails into "conversations" > - No pop-up ads or untargeted banners - just text ads and related information > that are relevant to the content of your messages > > All this, and its yours for free. But wait, there's more! By opening a Gmail > account, you also get access to Google Talk, Google's instant messaging > service: > > http://www.google.com/talk/ > > Google Talk offers: > - Web-based chat that you can use anywhere, without a download > - A contact list that's synchronized with your Gmail account > - Free, high quality PC-to-PC voice calls when you download the Google Talk > client > > Gmail and Google Talk are still in beta. We're working hard to add new features > and make improvements, so we might also ask for your comments and suggestions > periodically. We appreciate your help in making our products even better! > > Thanks, > The Google Team > > To learn more about Gmail and Google Talk, visit: > http://mail.google.com/mail/help/about.html > http://www.google.com/talk/about.html > > (If clicking the URLs in this message does not work, copy and paste them into > the address bar of your browser). > ___ > Tutor maillist - Tutor@python.org > http://mail.python.org/mailman/listinfo/tutor > ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] what does the "@" operator mean?
On Tue, 16 Dec 2008 01:03:55 +, Alan Gauld wrote: > "Marc Tompkins" wrote > >> If you're just starting out in Python, decorators can be hard to get >> your head around... > > I've been using Python for oover 10 years and still find decorators hard > to get my head around! :-) > > I confess I'm not a fan, they go against the Python spirit of explicit > is best in my opinion. If I'm calling a function I like to know I'm > calling a function... I know they make the code look pretty but IMHO > they are a pain to debug and I'm never totally convinced I've got it > exactly right. I usually think about decorator as a tag or marker instead of function calling. When I put the property decorator, I'll be thinking about attaching a property tag to the function so the interpreter would handle the function as if it is a property. This way, I don't think of it as implicit function calling but as an explicit tag (how the tag system works is a detail I need not to care). ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] what does the "@" operator mean?
Am 16.12.2008 02:03, Alan Gauld schrieb: "Marc Tompkins" wrote If you're just starting out in Python, decorators can be hard to get your head around... I've been using Python for oover 10 years and still find decorators hard to get my head around! :-) I confess I'm not a fan, they go against the Python spirit of explicit is best in my opinion. If I'm calling a function I like to know I'm calling a function... I know they make the code look pretty but IMHO they are a pain to debug and I'm never totally convinced I've got it exactly right. Alan G Just found this via dzone.org: http://gumuz.nl/weblog/simple-python-decorator-classes/ Very interesting read. HTH, Wolfram ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Lucky Boy Sudhir wants to chat
I have unsubscribed Lucky Boy from the list as he is just spamming it. Kent On Wed, Dec 17, 2008 at 7:01 AM, Lucky Boy Sudhir wrote: > --- > > Lucky Boy Sudhir wants to stay in better touch using some of Google's > coolest new > products. > > If you already have Gmail or Google Talk, visit: > http://mail.google.com/mail/b-4696b4693-d5d69810df-aafd3a6b94976b5f > You'll need to click this link to be able to chat with Lucky Boy Sudhir . > > To get Gmail - a free email account from Google with over 2,800 megabytes of > storage - and chat with Lucky Boy Sudhir , visit: > http://mail.google.com/mail/a-4696b4693-d5d69810df-ee3cdf55e5 > > Gmail offers: > - Instant messaging right inside Gmail > - Powerful spam protection > - Built-in search for finding your messages and a helpful way of organizing > emails into "conversations" > - No pop-up ads or untargeted banners - just text ads and related information > that are relevant to the content of your messages > > All this, and its yours for free. But wait, there's more! By opening a Gmail > account, you also get access to Google Talk, Google's instant messaging > service: > > http://www.google.com/talk/ > > Google Talk offers: > - Web-based chat that you can use anywhere, without a download > - A contact list that's synchronized with your Gmail account > - Free, high quality PC-to-PC voice calls when you download the Google Talk > client > > Gmail and Google Talk are still in beta. We're working hard to add new > features > and make improvements, so we might also ask for your comments and suggestions > periodically. We appreciate your help in making our products even better! > > Thanks, > The Google Team > > To learn more about Gmail and Google Talk, visit: > http://mail.google.com/mail/help/about.html > http://www.google.com/talk/about.html > > (If clicking the URLs in this message does not work, copy and paste them into > the address bar of your browser). > ___ > Tutor maillist - Tutor@python.org > http://mail.python.org/mailman/listinfo/tutor > ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Lucky Boy Sudhir has invited you to open a Google mail account
I've been using Gmail and thought you might like to try it out. Here's an invitation to create an account. --- Lucky Boy Sudhir has invited you to open a free Gmail account. To accept this invitation and register for your account, visit http://mail.google.com/mail/a-4696b4693-1006ddb730-25c77422c3 Once you create your account, Lucky Boy Sudhir will be notified with your new email address so you can stay in touch with Gmail! If you haven't already heard about Gmail, it's a new search-based webmail service that offers: - Over 2,700 megabytes (two gigabytes) of free storage - Built-in Google search that instantly finds any message you want - Automatic arrangement of messages and related replies into "conversations" - Powerful spam protection using innovative Google technology - No large, annoying ads--just small text ads and related pages that are relevant to the content of your messages To learn more about Gmail before registering, visit: http://mail.google.com/mail/help/benefits.html And, to see how easy it can be to switch to a new email service, check out our new switch guide: http://mail.google.com/mail/help/switch/ We're still working every day to improve Gmail, so we might ask for your comments and suggestions periodically. We hope you'll like Gmail. We do. And, it's only going to get better. Thanks, The Gmail Team (If clicking the URLs in this message does not work, copy and paste them into the address bar of your browser). ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Lucky Boy Sudhir wants to chat
--- Lucky Boy Sudhir wants to stay in better touch using some of Google's coolest new products. If you already have Gmail or Google Talk, visit: http://mail.google.com/mail/b-4696b4693-d5d69810df-aafd3a6b94976b5f You'll need to click this link to be able to chat with Lucky Boy Sudhir . To get Gmail - a free email account from Google with over 2,800 megabytes of storage - and chat with Lucky Boy Sudhir , visit: http://mail.google.com/mail/a-4696b4693-d5d69810df-ee3cdf55e5 Gmail offers: - Instant messaging right inside Gmail - Powerful spam protection - Built-in search for finding your messages and a helpful way of organizing emails into "conversations" - No pop-up ads or untargeted banners - just text ads and related information that are relevant to the content of your messages All this, and its yours for free. But wait, there's more! By opening a Gmail account, you also get access to Google Talk, Google's instant messaging service: http://www.google.com/talk/ Google Talk offers: - Web-based chat that you can use anywhere, without a download - A contact list that's synchronized with your Gmail account - Free, high quality PC-to-PC voice calls when you download the Google Talk client Gmail and Google Talk are still in beta. We're working hard to add new features and make improvements, so we might also ask for your comments and suggestions periodically. We appreciate your help in making our products even better! Thanks, The Google Team To learn more about Gmail and Google Talk, visit: http://mail.google.com/mail/help/about.html http://www.google.com/talk/about.html (If clicking the URLs in this message does not work, copy and paste them into the address bar of your browser). ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] How to exit program without sys.exit()
Hi,
I make these silly programs to learn from examples I find on the list. I
put a couple together just to practice. I have heard it is not a good
idea to use sys.exit() but I can not figure out how to do it. Also any
and all comments are welcome. Thanks
#!/usr/bin/python
import sys
_count = 0
def getinfo():
answer = yesno("Enter y to continue, n to exit: y/n >> ")
if answer == "y":
getnumber()
else:
sys.exit()
def counter():
global _count
_count += 1
return _count
def yesno(question):
responce = None
while responce not in ("y", "n"):
responce = raw_input(question).lower()
return responce
def getnumber():
try:
num = int(raw_input("Enter a number between 25 and 75: "))
if 25 < num < 75:
print "WOW you are smart ", sayit()
except ValueError:
print "Please Enter a number!", getnumber()
def sayit():
print "Your total correct answers is", counter()
again()
def again():
onemore = raw_input("Again? y/n >> " )
if onemore.lower() == "y":
getnumber()
elif onemore.lower() == "n":
getinfo()
else:
sys.exit
def main():
getinfo()
if __name__=="__main__":
main()
--
Powered by Gentoo GNU/LINUX
http://www.linuxcrazy.com
pgp.mit.edu
___
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] How to exit program without sys.exit()
> I make these silly programs to learn from examples I find on the list. I put
> a couple together just to practice. I have heard it is not a good idea to
> use sys.exit() but I can not figure out how to do it. Also any and all
> comments are welcome. Thanks
david,
welcome to Python! it's definitely a good thing to read this list and
even more importantly, to practice. as far as your inquiry goes, you
don't need *any* sys.exit() calls in your code. just remove them plus
the else statement above each, as in:
> #!/usr/bin/python
> import sys
> _count = 0
>
> def getinfo():
>answer = yesno("Enter y to continue, n to exit: y/n >> ")
>if answer == "y":
>getnumber()
>
> def counter():
>global _count
>_count += 1
>return _count
>
> def yesno(question):
>responce = None
>while responce not in ("y", "n"):
>responce = raw_input(question).lower()
>return responce
>
> def getnumber():
>try:
>num = int(raw_input("Enter a number between 25 and 75: "))
>if 25 < num < 75:
>print "WOW you are smart ", sayit()
>except ValueError:
>print "Please Enter a number!", getnumber()
>
>
> def sayit():
>print "Your total correct answers is", counter()
>again()
>
>
> def again():
>onemore = raw_input("Again? y/n >> " )
>if onemore.lower() == "y":
>getnumber()
>elif onemore.lower() == "n":
>getinfo()
>
> def main():
>getinfo()
>
> if __name__=="__main__":
>main()
it should still work the same as before. your functions will return
to the caller, and they will exit in the same way. finally, when
main() is done, your app is automatically exits.
one other suggestion... you have a lot of functions. it's possible to
reduce the total number, esp. since they're pretty much all one-offs.
generally, you want to employ functions for code that is used more
than once during a single execution of your code. with your app, you
can probably get away with not having any functions at all.
cheers,
-- wesley
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
"Core Python Programming", Prentice Hall, (c)2007,2001
"Python Fundamentals", Prentice Hall, (c)2009
http://corepython.com
wesley.j.chun :: wescpy-at-gmail.com
python training and technical consulting
cyberweb.consulting : silicon valley, ca
http://cyberwebconsulting.com
___
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] How to exit program without sys.exit()
"David" wrote put a couple together just to practice. I have heard it is not a good idea to use sys.exit() sys.exit is there to exit from a program so there is absolutely nothing wrong with using it. However the way you are using it is not optimal. A program will terminate or exit by itself if you allow it to "run off the end". So you can remove most of your sys.exit() calls. Where you want to use sys.exit() is where something happens that would leave your program running but in a state where it might then do some damage or produce a wriong result. You can then force a premature exit with sys.exit. However even in these cases it's often possible to restructure your code so that an explicit call to sys.exit is not needed. So to answer your question, using sys.exit is not bad or wrong, but mostly you don't need to. It's better to reserve its use for occasions where the program has to be forced to exit early. The other place where you should use sys.exit() is where you want to return a specific error code to the Operating System - usually for other scripts to use to detect errors by your program. HTH, -- Alan Gauld Author of the Learn to Program web site http://www.freenetpages.co.uk/hp/alan.gauld ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] How to exit program without sys.exit()
one other suggestion... you have a lot of functions. it's possible to reduce the total number, esp. since they're pretty much all one-offs. generally, you want to employ functions for code that is used more than once during a single execution of your code. with your app, you can probably get away with not having any functions at all. cheers, -- wesley I was practicing how to use a global counter and trying to understand how functions can interact with each other. I can understand if I can see the error's when I run the program. I know my terminology may be hard to follow. Also I like your book :) So to answer your question, using sys.exit is not bad or wrong, but mostly you don't need to. It's better to reserve its use for occasions where the program has to be forced to exit early. The other place where you should use sys.exit() is where you want to return a specific error code to the Operating System - usually for other scripts to use to detect errors by your program. HTH, -- Alan Gauld Author of the Learn to Program web site http://www.freenetpages.co.uk/hp/alan.gauld Thanks, That does HAL (help a lot). Also thanks for the tutorial/book I have it bookmarked :) -david -- Powered by Gentoo GNU/LINUX http://www.linuxcrazy.com pgp.mit.edu ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] How to exit program without sys.exit()
> I was practicing how to use a global counter and trying to understand > how functions can interact with each other. I can understand if I can > see the error's when I run the program. I know my terminology may be > hard to follow. Also I like your book :) you are well read since you already have seen places where it is suggested that using sys.exit() is not the best choice. as alan has said, there isn't anything really "evil" about it... it just not necessary, and you can write applications without using it at all. another thing you'll read about is how it's "not good" to have global variables. as with sys.exit() it is possible to have a universal counter without using a global variable. they are a bit worse than sys.exit() because they take up extra memory, there is less control -- they can be updated in multiple places in an application; such access may result in race conditions and unexpected behavior if modified by concurrent threads, etc. to find a suitable replacement will depend on what you're counting, and where a better place may be to store the counter. for example, you can use a static member of a class, a closure, etc. if you have specific application requirements, just post them to the list, and folks will be glad to help you get around using global counters. glad you enjoy the book! pssst... there is a DVD version of it coming out at the end of this month called "Python Fundamentals"... keep an eye out for it! ;-) best regards, -- wesley - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - "Core Python Programming", Prentice Hall, (c)2007,2001 "Python Fundamentals", Prentice Hall, (c)2009 http://corepython.com wesley.j.chun :: wescpy-at-gmail.com python training and technical consulting cyberweb.consulting : silicon valley, ca http://cyberwebconsulting.com ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
