Pythonic way to determine whether not null list entries are 'continuous'

Question

I\'m looking for a way to easily determine if all not None items in a list occur in a single continuous slice. I\'ll use integers as examples of not None items

Answer 1

The natural way to consume sequence elements is to use dropwhile:

from itertools import dropwhile
def continuous(seq):
    return all(x is None for x in dropwhile(lambda x: x is not None,
                                            dropwhile(lambda x: x is None, seq)))

We can express this without nested function calls:

from itertools import dropwhile
def continuous(seq):
    core = dropwhile(lambda x: x is None, seq)
    remainder = dropwhile(lambda x: x is not None, core)
    return all(x is None for x in remainder)