Intro to
Programming
with Python

Fall 2010
course
navigation

questions

Anyone in the class edit this page. Brownie points for both good questions and good answers.

your question

... can go here.

Can I type python code into one of these wiki pages?

Yup. See this python formatting example.

Where do I put the graphics.py module so that things work?

If the current folder doesn't work (or you're using an IDE, i.e. double-clicking something to run python - and can't tell what the current folder is), you can find a list of folders where python looks for things to import by doing this: >>> import sys >>> print sys.path # print a list of folders where I can put graphics.py >>> import os >>> print os.getcwd() # print the current directory

What is a "domain error", and why do I get it in this line

a = sqrt( b^2 + c^2)
A "domain error" means that you're doing something math-ish with out of range arguments, like trying to take the square root of a negative number. Here the problem is that b^2 doesn't mean "b squared", it means "b bitwise_xor 2", which is quite different, and might be negative. In python, "b squared" is written b**2.

How do loops work in doctests?

Answer: put 'em in the doctest exactly as they look from an interactive prompt:
""" >>> for i in range(3): ... print i ... 0 1 2 """ import doctest doctest.testmod()

How do you use assertions? Can they go in doctest?

Answer: like this. And yes. """ In a doctest; success doesn't print anything. >>> assert 1==1 """ import doctest doctest.testmod() # in python code, with an (optional) failure message: assert 1==2, "one isn't two"
http://cs.marlboro.edu/ courses/ fall2010/python/ wiki/ questions
last modified Monday November 15 2010 12:07 am EST