🌐 Mailman 3 June 2003 - Tutor - python.org

Backslashes inside of variable
by Phoebus Nov. 24, 2003

Nov. 24, 2003

I am running Python 2.2 on Win2k. I have a program which writes a filename, with backslashes to a file, along with other stuff. I read the file in using readlines() and put each line into a variable. My problem is I want to use the filename, but I can't use it because of the backslashes. I know about doing open(r"d:\test\file.txt","w") or even open(`d:\test\file.txt`,"w"), but the filename is inside of a variable so when I do open(filename,'w'), I have problems. Can anyone help? Thanks, Steve --

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newbie re question
by tpc＠csua.berkeley.edu July 8, 2003

July 8, 2003

hi Danny, I had a question about your quick intro to Python lesson sheet you gave out back in March 2001. The last page talks about formulating a regular expression to handle URLs, and you have the following: myre = re.compile(r'http://[\w\.-/]+\.?(?![\w.-/])') I understand \w stands for any word character, and \. means escaped period, and ? means zero or one instances of a character or set. I did a myre.search('http://www.hotmail.com') which yielded a result, but I am confused as to why myre.search('http://www.sfgate.com/cgi-bin/article.cgi?f=/gate/archive/2003/06/29/gavin2…') would work, since there is a '=' and you don't provide for one in the regular expression. I guess I also am confused why you have a '(?!' after you allow for zero or one period.

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finding factorials
by Payal Rathod July 1, 2003

July 1, 2003

Hi, I am very new to python and programming in general. I was reading a tutorial "Programming in Python" in which the author has asked the reader an problem which I am unable to get. Problem is as follow, Write a function that implements Euclid's method for finding a common factor of two numbers. It works like this: 1. You have two numbers, a and b, where a is larger than b 2. You repeat the following until b becomes zero: 1. a is changed to the value of b 2. b is changed to the remainder when a (before the change) is divided by b (before the change) 3. You then return the last value of a My very basic solution is going totally wrong, #!/usr/local/bin/python def euclid(a,b): c = a a = b b = c % a if b != 0: euclid(a,b) return a b = 5 euclid(10,5) print a It is giving errors. Can someone guide me to a proper solution? Thanks a lot and hope this basic question is allowed. Please make a CC to me also. With warm regards, -Payal -- "Visit GNU/Linux Success Stories" http://payal.staticky.com Guest-Book Section Updated.

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writing a search engine
by Kyle Babich July 1, 2003

July 1, 2003

Any suggestions on where to start? I plan on writing one for a small site of mine. It will basically be "google-style"- simple and functional. The item being searched will be text files, where users can search based on title, contents, or both. I was reading through some books but I'm stumped on where to begin. I've never tried writing something even similar to a search engine and I guess I'm little confused/overwhelmed/bewildered. :) You guys always come to the rescue for me, so how about one more time? -- Kyle

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Shebang problem
by Rick Thomas July 1, 2003

July 1, 2003

Hi, I'm very new to programming and am plodding my way through Alan Gauld's book 'Learn to Program Using Python'. At present I can't get my programs to execute using the Shebang trick. #!/usr/bin/python My scripts ran fine when I was using SuSE 7.3 but I've recently upgraded to 8.3 and wondered if this is somehow the problem. My scripts run ok if I type for example 'python foo.py' in a terminal. Any advice would be much appreciated. Rick Thomas

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readlines code
by Cliff Martin June 30, 2003

June 30, 2003

Hi, I'm trying to read in an ASCII file of a fairly large set of data with data separated by spaces and each line ending with a linefeed. If I use readlines() I get all the data but each line still has a \n tacked on. If I use: f=open("c:/transfer/filename") for line in f.readlines(): words=line.rstrip().split() I get only the last line of the file in words. Could someone explain why this is happening? There is something about the use of Python here that I'm not understanding. Thanks for any help. Cliff Martin

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newbie 'while' question
by Matthew Richardson June 30, 2003

June 30, 2003

I'm working through Josh Cogliati's tutorial and Wesley Chun's book to learn Python. So far things have been going smoothly, easy to say since I've only hit the third chapter. However, I'm stuck on an easy problem and it's causing me grief because I know it should be easy. The exercise is to take a string that is inputted by the user and print each letter of the string individually, solve with a 'for' and a 'while.' The 'for' was easy: s = raw_input('Enter a name: ') for x in s: print x Trying to do it with 'while', I've only managed to get it to print through to the last character, where it loops and continues to print the last character until escaped. Someone willing to point me in the right direction? Thanks, Matt -- Matt Richardson Instructional Support Technician Department of Art CSU San Bernardino

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Convert list to literal string.
by Decibels June 30, 2003

June 30, 2003

Having a little problem with part of my program. I had a little setup program I wrote to populate a database. In the setup I used literal strings for the symbols, and figured later I would have it take command-line options for them. Problem is now, I can't get the function to work with the list, only if I enter the data as literal strings. Example: stocks = "IBM,EK" send that to the yahooquotes module and works fine! When I enter them from the command-line though it doesn't It comes as a list and won't work. Is there a way to make a list into a literal? Thanks, Dave

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Re: [Tutor] python exe files
by GREENDAY31087＠aol.com June 30, 2003

June 30, 2003

In a message dated 6/27/03 11:19:03 AM Pacific Daylight Time, jeff(a)ccvcorp.com writes: > >pythonw.exe - what is this??? > > > > This is a console-less version of the interpeter -- it's a Windows-style > app rather than a DOS-style app (as python.exe is). This means that if, > for instance, your Python script has a GUI and opens its own windows, > etc, then you can run it in pythonw.exe and it won't have an ugly and > otherwise useless DOS box open as well. > > I have a few GUIs. How would I run them with pythonw.exe? -Wayne (win98)

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RE: [Tutor] Function Programming Style
by Alan Trautman June 30, 2003

June 30, 2003

> In addition, if you combine all of your set functions into on gigantic > function it will be much harder to debug and/or add features. >After reading your message serveral times: do you recommend smaller >set/get functions or not? Maybe my initial mail lacked some >informations. Sorry I guess I didn't make it clear enough. Monday and all. Yes, I recommend the small functions as a building block for larger ones. For Examples time function in pseudo code: Class time: __init__(self): hour = 0 minute = 0 second = 0 def setHour(self, hour) if hour is between 1 and 12: self.hour = hour else: some error thing Do the same for minute and second. However, you might also create a function called set time to do all three at once: def setTime(hour, min, sec): setHour(hour) setMinute(min) setSec(sec) For when you want to set all three and you do not have to rewrite the error checking and you can combine them in any combination desired or add additional error checking for the higher level function. >I know Python does not need get/set but this is a common way of >accessing variables even if they "private", isn't it? Yes very common especially in microsoft environoments. Many formal textbooks say it should always be done. I am writing a GUI application which sets some meta informations on files. There is a class for the information and one for the GUI. The GUI just calls fileinfo.set_date(), fileinfo.set_url() and so on. >I now believe, this is the way to go: small, simple functions to >fullfill the KISS paradigm. I agree and one of the great things about Python is that all of the functionality does not have to be embedded in the GUI so you can build a fully functional non-GUI version first and attach the GUI later to split the testing so you can determine if it is a GUI or program error. Kai -- * mail kai.weber(a)glorybox.de web http://www.glorybox.de pgp 0x594D4132 _______________________________________________ Tutor maillist - Tutor(a)python.org http://mail.python.org/mailman/listinfo/tutor

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