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pythonlist-comprehensionpython-2.6

List Comprehension: why is this a syntax error?


Why is print(x) here not valid (SyntaxError) in the following list-comprehension?

my_list=[1,2,3]
[print(my_item) for my_item in my_list]

To contrast - the following doesn't give a syntax error:

def my_func(x):
    print(x)
[my_func(my_item) for my_item in my_list]

Solution

  • Because print is not a function, it's a statement, and you can't have them in expressions. This gets more obvious if you use normal Python 2 syntax:

    my_list=[1,2,3]
    [print my_item for my_item in my_list]
    

    That doesn't look quite right. :) The parenthesizes around my_item tricks you.

    This has changed in Python 3, btw, where print is a function, where your code works just fine.