Properly setting Vim up for Python coding

There is actually some incorrect information in there:

    Vim already has built in syntax highlighting for python
    but I have a small tweak to vim to give you notifications 
    of small syntax errors like forgetting a colon after a for 
    loop. Create a file called ~/.vim/syntax/python.vim and 
    add the following into it:

That will override the system's version of python.vim. Using ~/.vim/after/syntax/python.vim or even something like ~/.vim/after/syntax/python/custom_errors.vim will do the trick.