You could use textwrap module:

>>> import textwrap
>>> strs = "In my project, I have a bunch of strings that are read in from a file. Most of them, when printed in the command console, exceed 80 characters in length and wrap around, looking ugly."
>>> print(textwrap.fill(strs, 20))
In my project, I
have a bunch of
strings that are
read in from a file.
Most of them, when
printed in the
command console,
exceed 80 characters
in length and wrap
around, looking
ugly.

help on textwrap.fill:

>>> textwrap.fill?

Definition: textwrap.fill(text, width=70, **kwargs)
Docstring:
Fill a single paragraph of text, returning a new string.

Reformat the single paragraph in 'text' to fit in lines of no more
than 'width' columns, and return a new string containing the entire
wrapped paragraph.  As with wrap(), tabs are expanded and other
whitespace characters converted to space.  See TextWrapper class for
available keyword args to customize wrapping behaviour.

Use regex if you don't want to merge a line into another line:

import re


strs = """In my project, I have a bunch of strings that are.
Read in from a file.
Most of them, when printed in the command console, exceed 80.
Characters in length and wrap around, looking ugly."""

print('\n'.join(line.strip() for line in re.findall(r'.{1,40}(?:\s+|$)', strs)))

# Reading a single line at once:
for x in strs.splitlines():
    print '\n'.join(line.strip() for line in re.findall(r'.{1,40}(?:\s+|$)', x))

output:

In my project, I have a bunch of strings
that are.
Read in from a file.
Most of them, when printed in the
command console, exceed 80.
Characters in length and wrap around,
looking ugly.