Working my way into Python (2.7.1) But failing to make sense (for hours) of this:
>>> a = [1, 2]
>>> b = [3, 4]
>>>
>>> a.extend([b[0]])
>>> a
[1, 2, 3]
>>>
>>> a.extend([b[1]])
>>> a
[1, 2, 3, 4]
>>>
>>> m = [a.extend([b[i]]) for i in range(len(b))] # list of lists
>>> m
[None, None]
The first two extends work as expected, but when compacting the same in a list comprehension it fails. What am i doing wrong?
extend
modifies the list in-place.
>>> [a + b[0:i] for i in range(len(b)+1)]
[[1, 2], [1, 2, 3], [1, 2, 3, 4]]
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