list.remove() returns None. So it is a mistake to bind its return value to allbu... | Hacker News

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d0mine on Nov 6, 2011 | parent | context | favorite | on: Python: copying a list the right way

list.remove() returns None. So it is a mistake to bind its return value to allbut2.

It follows the convention that methods that modify their object inplace should return None. list.pop() is an obvious exception.

You create a new list via list comprehension instead of copying and then removing:

  even = [i for i in L if i % 2 == 0] # remove odd numbers

tedunangst on Nov 6, 2011 [–]

I believe he meant:

    all = range()
    allbut2 = all
    allbut2.remove(2)

which is something that catches people all the time.

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