Is there a Pythonic way to create a list of cloned items?

Question

Consider the following code:

class SomeClass:
    def __init__(self):
        self.foo = None

some_list = [SomeClass()] * 5

The problem with this code is that all 5 items of some_list refer to the same instance of SomeClass. If I do some_list[0].foo = 7, then I get some_list[1].foo equal to 7, etc.

So how to instantiate N different SomeClass instances in a list?

You're trying to create a list of class instances. "Cloned" implies, at least to me, references to the same object in memory — roganjosh, Jan 10 '19 at 20:03

score 3 · Accepted Answer · answered Jan 10 '19 at 19:16

3

Solution: use list comprehension

class SomeClass:
    def __init__(self):
        self.foo = None

some_list = [SomeClass() for _ in range(5)]

answered Jan 10 '19 at 19:16

Jordan Singer

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Is there a Pythonic way to create a list of cloned items?

1 Answers1