🌐 Mailman 3 May 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 --

4 6

unit testing
by Tom Plunket June 1, 2003

June 1, 2003

I have just been getting into Python, but one of the most infuriating things that I've come across is that I cannot for the life of me figure out how to easily write unit test code that automatically gets loaded and imported at runtime. As a C++ pro, CppUnit did exactly what I wanted it to do, and there was never any question. PyUnit, however... My test.py is pretty much ripped off from the regrtest.py found in Py22's test unit (although I also don't understand why I can't import test.regrtest): #!/usr/bin/python, but I'm on Windows. :) import unittest import os if __name__ == "__main__": names = os.listdir('.') tests = [] for name in names: if name[:5] == "test_" \ and name[-3:] == os.extsep+"py": modname = name[:-3] tests.append(modname) tests.sort() for test in tests: module = __import__(test, globals(), locals(), []) unittest.main() Now if I get rid of all of this hooplah and manually import unittest from test_something import * from test_somethingelse import * if __name__ == "__main__": unittest.main() then everything works. Why isn't my code pulling my tests into my local namespace? I really don't want to have to maintain this (with CppUnit I could have test files that had no external dependencies, I just had to link them into the project and everything would start getting tests run. I want to just have all tests in every test_* file run automatically.) Additionally- why is it that unittest throws an exception when it ends properly? Why on earth can't it be nice and procedural and just allow execution to return normally? (Mind you, I am probably not "getting" Python yet, but that will come!) thanks. -tom!

4 7

recursion sort of
by Jennifer Cianciolo June 1, 2003

June 1, 2003

Hi all, I'm trying to write a little program on population growth (of anything, say plants). The key is that it's frequency dependent. When the size is large, individuals don't do as well, and then when it's smaller, they do better. also there are 2 'types' of individuals (here called n1 and n2; 'w' is how well they do) Here it is so far: def run(n1, n2): while n1>=501: w=1 n1=n1*w while n1<=500: w=0.2 n1=n1*W while n2>=501: w=0.8 n2=n2*w while n2<=500: w=0.4 n2=n2*W nt=n2+n1 print nt now 2 problems, it is making python freeze again, and I'm sure if I could run it like this it would say n2 is called before it is defined (or something like that) but I don't think I want to put it in the loop, do I? I would also want it to keep measuring nt over time, but I think I can work on that more myself, if I can get around getting it to calculate nt once in the first place. Any suggustions? I hope this isn't too vague. thanks in advance Jen

9 18

Installing gnome-python/conflicts with old python versions trouble
by ashleigh smythe June 1, 2003

June 1, 2003

Hello! I'm trying to install gnome-python-1.99.16. My Linux came with python1.5 (in /usr/lib) but I installed python2.2 in /usr/local/lib. I'm using 2.2 for all my python learning. I read somewhere (Red Hat info?) that I should leave the python1.5 on my system as Red Hat might need to use it. Of course that was _after_ I deleted some of the 1.5 files! Nevertheless, now when I try to install gnome-python, it seems like it finds 2.2 but also 1.5 and gives me error messages indicating that my python libraries are too old. I have had similar problems installing additional python modules as I'm just not clear on where they (or frankly anything else I install!) should go - I put biopython into /usr/local/lib/python2.2/site-packages but python2.2 can't find my input files in my home directory, only if they are also in /site-packages. I tried some of the options offered in ./config -- help but they didn't seem to help (but I could just be misunderstanding them as I am still pretty lame with general Linux/bash stuff!). Long configure message after my ./config is below. Thanks for any ideas/explanations! Ashleigh [ashleigh@nate gnome-python-1.99.16]$ ./configure checking for a BSD-compatible install... /usr/bin/install -c checking whether build environment is sane... yes checking for gawk... gawk checking whether make sets $(MAKE)... yes checking build system type... i686-pc-linux-gnu checking host system type... i686-pc-linux-gnu checking for style of include used by make... GNU checking for gcc... gcc checking for C compiler default output... a.out checking whether the C compiler works... yes checking whether we are cross compiling... no checking for suffix of executables... checking for suffix of object files... o checking whether we are using the GNU C compiler... yes checking whether gcc accepts -g... yes checking for gcc option to accept ANSI C... none needed checking dependency style of gcc... gcc3 checking for ld used by GCC... /usr/bin/ld checking if the linker (/usr/bin/ld) is GNU ld... yes checking for /usr/bin/ld option to reload object files... -r checking for BSD-compatible nm... /usr/bin/nm -B checking for a sed that does not truncate output... /bin/sed checking whether ln -s works... yes checking how to recognise dependent libraries... pass_all checking command to parse /usr/bin/nm -B output... ok checking how to run the C preprocessor... gcc -E checking for egrep... grep -E checking for ANSI C header files... yes checking for sys/types.h... yes checking for sys/stat.h... yes checking for stdlib.h... yes checking for string.h... yes checking for memory.h... yes checking for strings.h... yes checking for inttypes.h... yes checking for stdint.h... yes checking for unistd.h... yes checking dlfcn.h usability... yes checking dlfcn.h presence... yes checking for dlfcn.h... yes checking for ranlib... ranlib checking for strip... strip checking for objdir... .libs checking for gcc option to produce PIC... -fPIC checking if gcc PIC flag -fPIC works... yes checking if gcc static flag -static works... yes checking if gcc supports -c -o file.o... yes checking if gcc supports -c -o file.lo... yes checking if gcc supports -fno-rtti -fno-exceptions... yes checking whether the linker (/usr/bin/ld) supports shared libraries... ./configure: =$CC -shared $libobjs $deplibs $compiler_flags ${wl}-soname $wl$soname -o $lib: command not found yes checking how to hardcode library paths into programs... immediate checking whether stripping libraries is possible... yes checking dynamic linker characteristics... GNU/Linux ld.so checking if libtool supports shared libraries... yes checking whether to build shared libraries... yes checking whether to build static libraries... no checking whether -lc should be explicitly linked in... no creating libtool checking for python... /usr/bin/python checking for python version... 1.5 checking for python platform... linux-i386 checking for python script directory... ${prefix}/lib/python1.5/site-packages checking for python extension module directory... ${exec_prefix}/lib/python1.5/site-packages checking for python >= 2.2... configure: error: too old

2 1

-Recursive Functions
by evros loizides June 1, 2003

June 1, 2003

* Your program should accept a string using the raw_input function. It should define a RECURSIVE function stringToNum(aString) than accepts a string parameter and returns the sum of the digit characters that occur in the string. Thus, e.g., if the input is 'he5llo7 9world', the return value would be 21 this the part i cannot amke it work with recursive fuction my program work using while loop. anybody ahs any ideas how to use recursive fuction? can email me any suggestions at loizie(a)hotmail.com

3 2

Recursive function(posting the output of teh code)
by evros loizides May 31, 2003

May 31, 2003

enter string:erfe7er6e9eve09 erfe7er6e9eve09 15 31 what this program does gets the digits form a string add them and print teh sum evrything okey until i have to use recursive function taht i am not familiar with how does it work . Any good reference on recursive functions taht will be helpfull too. thanks

3 2

recursive function
by evros loizides May 31, 2003

May 31, 2003

i need to use recursive fuction insted of while loop in the following program . does anybody have any good ideas how to do that? #def isString() import string myString = raw_input("enter string:") num=len(myString) print myString print len(myString) n=1 sum=0 while n<=num: if myString[n-1].isdigit(): #print "is digit" sum=sum+int(myString[n-1]) #print sum #else: #print "is not digit" n=n+1 print sum

2 1

RE: [Tutor] help on newbie program
by Nick Jensen May 31, 2003

May 31, 2003

-----Original Message----- From: Randy Talbot [mailto:randytalbot@comcast.net] Sent: Sat 5/31/2003 10:02 AM To: Python Cc: Subject: RE: [Tutor] help on newbie program > A paper book can never keep up to date with something like Python, but > Learning Python needs a 2nd edition that covers 2.3 to stay useful. > It's a bit sad to learn stuff, just to unlearn them as we turn to the > next book. >>Learning Python is coming out with a 2nd edition. Amazon.com has a>> >>possible release date of July 2003 with the book's ISBN # as 0596002815. >>Randy Yep, I saw this and think I'll wait for it to come out. The first edition got really high ratings and since it focuses just on python and is for newbies it seems to be exactly what I want. Thanks -Nick _______________________________________________ Tutor maillist - Tutor(a)python.org http://mail.python.org/mailman/listinfo/tutor

2 1

c struct with python
by Mehta, Anish May 31, 2003

May 31, 2003

Hello ! I have a c structure which i am representing with a class in python. The structure is of the form: typedef struct abc { void (*XY)(int a, int b); }ABC; void XY(int a, int b) { # code here } Can someone tell me how this can be handled in python. Thanks in advance. Regards, Anish MEHTA.

2 1

help on newbie program
by Nick Jensen May 31, 2003

May 31, 2003

Hello, I'm just starting to learn programming and python is my first language. I've been using Josh Cogliati's guide: "Non-Programmers Tutorial For Python" with a url of http://www.honors.montana.edu/~jjc/easytut/easytut/node10.html which is linked off from www.python.org under beginners guide. I have read every example and line of code up to and including the section on lists, but I just cannot understand the last example in that section named test.py. I understand parts of it, but not all of it as a whole. I'm not able to follow the flow of the program and whats happening at each step. Maybe I'm asking too much, but was wondering if anyone could walk me through the code and whats happening. By the way, I did send an email to Josh asking this same question, but not sure if I'll hear back or not and thought I'd ask here just in case. Here it is... Thanks! test.py ## This program runs a test of knowledge true = 1 false = 0 # First get the test questions # Later this will be modified to use file io. def get_questions(): # notice how the data is stored as a list of lists return [["What color is the daytime sky on a clear day?","blue"],\ ["What is the answer to life, the universe and everything?","42"],\ ["What is a three letter word for mouse trap?","cat"]] # This will test a single question # it takes a single question in # it returns true if the user typed the correct answer, otherwise false def check_question(question_and_answer): #extract the question and the answer from the list question = question_and_answer[0] answer = question_and_answer[1] # give the question to the user given_answer = raw_input(question) # compare the user's answer to the testers answer if answer == given_answer: print "Correct" return true else: print "Incorrect, correct was:",answer return false # This will run through all the questions def run_test(questions): if len(questions) == 0: print "No questions were given." # the return exits the function return index = 0 right = 0 while index < len(questions): #Check the question if check_question(questions[index]): right = right + 1 #go to the next question index = index + 1 #notice the order of the computation, first multiply, then divide print "You got ",right*100/len(questions),"% right out of",len(questions) #now lets run the questions run_test(get_questions())

2 1