invert edge values in python boolean list

Question

I have a list of booleans like

l = [False, False, False, True, True, True, False, False, True, False, False]

and want to invert every edge value that is False like

[True, True, True, True, True, True, False, False, True, True, True]

What is the most pythonic way to achieve that?

Answer 1

Possibly there's some clever one-line solution for this, but until someone comes up with it, here's a way to do it with old fashioned iteration:

seq = [False, False, False, True, True, True, False, False, True, False, False]

for i in range(len(seq)):
    if seq[i]:
        break
    seq[i] = True

for i in range(len(seq)-1, -1, -1):
    if seq[i]:
        break
    seq[i] = True

print(seq)

Result:

[True, True, True, True, True, True, False, False, True, True, True]