Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
120 views
in Technique[技术] by (71.8m points)

python - Initialize list with same bool value

Is it possible without loops initialize all list values to some bool? For example I want to have a list of N elements all False.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

You can do it like this: -

>>> [False] * 10
[False, False, False, False, False, False, False, False, False, False]

NOTE: - Note that, you should never do this with a list of mutable types with same value, else you will see surprising behaviour like the one in below example: -

>>> my_list = [[10]] * 3
>>> my_list
[[10], [10], [10]]
>>> my_list[0][0] = 5
>>> my_list
[[5], [5], [5]]

As you can see, changes you made in one inner list, is reflected in all of them.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

2.1m questions

2.1m answers

60 comments

56.9k users

...