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Python Python Collections (2016, retired 2019) Lists Growing Lists

Mirza Gogic
Mirza Gogic
4,342 Points

Why is + ["list item"] different than += ["list item"]

Why is + ["list item"] different than += ["list item"].

Why is += ["list item"] permanent? and just + ["list item"] is not?

1 Answer

By using the += compound operator, you are assigning the result of the operation to the variable. If you were to just use the + operator, you would get the result of that operation, but it wouldn't be saved into that variable. an example in the shell:

>>> a = 10
>>> a + 5
15
>>> a
10
>>> a += 5
>>> a
15