Pep8

I fixed all PEP8 warnings and sneaked in a couple of common coding standards-things.

Note: I changed loads of this:

```
if variable != False:
    then_some()
```

to

```
if variable:
    then_some()
```

If it is really better to test for not being explicitly False, replace them with: `if variable is not False` or `if not variable is False`. This is not the same as `if variable != False`. More things than `False` can be falsey :smile: