list - What does locals()['_[1]'] mean in Python? -

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i saw 1 liner code claimed remove duplicates sequence:

u = [x x in seq if x not in locals()['_[1]']]

i tried code in ipython (with python 2.7), gave keyerror: '_[1]'

does ['_[1]'] mean special in python?

locals()['_[1]'] way access reference list comprehension (or generator) current result inside list comprehension.

it quite evil, can produce funny results:

>> [list(locals()['_[1]']) x in range(3)] [[], [[]], [[], [[]]]]

see more details here: the-secret-name-of-list-comprehensions.


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