Adherir al PEP 8 -- Style Guide for Python Code

ColombiaCasa.com's code should respect the Style Guide for Python Code: http://www.python.org/dev/peps/pep-0008/

This can be done in various stages. A non-exhaustive list of points to respect:
- Maximum Line Length (Limit all lines to a maximum of 79 characters.)
- Don't use spaces around the '=' sign when used to indicate a keyword argument or a default parameter value.
- Good documentation strings (a.k.a. "docstrings")
- Naming Conventions, particularly Function Names and Method Names and Instance Variables
- When catching exceptions, mention specific exceptions whenever possible instead of using a bare 'except:' clause.
- Don't compare boolean values to True or False using ==

Already done:
- Blank Lines
- Imports should usually be on separate lines
- Use ''.startswith() and ''.endswith() instead of string slicing to check for prefixes or suffixes.
- Comparisons to singletons like None should always be done with 'is' or 'is not', never the equality operators.