[python/en] Fix 80 col limit and clarify a few points.

I noticed a few missing features, some potentially misleading information, and some lines that were longer than 80 characters. This patch is my suggestion for fixes to these, although I'm happy to update anything which seems incorrect.

I'll add some comments to the diff.
The comments about the print statement versus the print function were incorrect and misleading. It's true that you can use the Python 3 print function in Python 2.7 but only if you use `from __future__ import print_function` at which point the regular print statement stops working. The patch has my attempt to stay concise and true to the original while fixing the misleading info.

Note that what looks like the print function syntax `print("x")` is really just the print statement printing a tuple of length 1 as a special case which only prints the element with no parens. `=> 'x'`
If you do `print('x','y')` you get `# => ('x', 'y')` because it is printing a tuple.

I think that IF we keep it this way it might be worth explaining the extra parameters to the print function. On the other hand, it might be better to just leave out any mention of the print function, because it's just clutter for a whirlwind tutorial.