Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

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

algorithm - Fast matrix transposition in Python

Is there any fast method to make a transposition of a rectangular 2D matrix in Python (non-involving any library import).?

Say, if I have an array

X=[ [1,2,3],
    [4,5,6] ]

I need an array Y which should be a transposed version of X, so

Y=[ [1,4],
    [2,5],
    [3,6] ] 
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 Reply

0 votes
by (71.8m points)

Simple: Y=zip(*X)

>>> X=[[1,2,3], [4,5,6]]
>>> Y=zip(*X)
>>> Y
[(1, 4), (2, 5), (3, 6)]

EDIT: to answer questions in the comments about what does zip(*X) mean, here is an example from python manual:

>>> range(3, 6)             # normal call with separate arguments
[3, 4, 5]
>>> args = [3, 6]
>>> range(*args)            # call with arguments unpacked from a list
[3, 4, 5]

So, when X is [[1,2,3], [4,5,6]], zip(*X) is zip([1,2,3], [4,5,6])


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…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...