Spacing

Indent with 4 spaces, not tabs

Limit lines to 80-100 characters:

No:

text = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. In a interdum ante. Vivamus blandit interdum justo a finibus. Fusce placerat ante nulla, eget malesuada magna tempor non. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur iaculis quis eros ultrices sagittis. Vivamus eget sem quis est ullamcorper dignissim.'

Yes:

text = ('Lorem ipsum dolor sit amet, consectetur adipiscing elit. In a interdum ante.'
        'Vivamus blandit interdum justo a finibus. Fusce placerat ante nulla, eget malesuada'
        'magna tempor non. Lorem ipsum dolor sit amet, consectetur adipiscing elit. '
        'Curabitur iaculis quis eros ultrices sagittis. Vivamus eget sem quis est ullamcorper dignissim.')

Use blank lines to separate functions and classes, and larger blocks of code inside functions:

No:

def f():
   ...
def g():
   ...
   ...

Yes:

def f():
   ...


def g():
   ...

   ...

Use spaces around operators and after commas, but not directly inside bracketing constructs:

No:

def f( a,g ):
    b=a
    return b[ g ]

Yes:

def f(a, g):
    b = a
    return b[g]