How to Append List to Empty List in Python? [duplicate]

Question

I try this code below

lst = [[]] * n
lst[0].append(1)

If i print the cod, the result is

[[1], [1], [1], [1], [1], [1]]

And then I try manual way to make an empty list like below

lst = [[], [], [], [], [], []]
lst[0].append(1)

The result showing up

[[1], [], [], [], [], []]

Is there any differences between lst = [[]] * n and lst = [[], [], [], [], [], []] ?

This exact question was just asked a few hours ago. :) stackoverflow.com/questions/60348228/… — Mateen Ulhaq
– Mateen Ulhaq, Commented Feb 22, 2020 at 10:36
Sorry, my friend, I'm new here, but I got it. I cant search the keyword for the article, so I made new one. Thanks for the response — Rijal Islami
– Rijal Islami, Commented Feb 23, 2020 at 4:31

kederrac · Accepted Answer · 2020-02-22 10:35:20Z

0

when you multiply your list of lists with n you are repeating only the reference to the same initial list so basically you have only one list and many references to the same list and when you are modifying one element you are modifying all; when you create "by hand" you have different lists

answered Feb 22, 2020 at 10:35

kederrac

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