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
385 views
in Technique[技术] by (71.8m points)

python - How to delete [NaN] from a list of lists?

I have the following

a = [[u'63764'], [u'63764'], [u'63764'], [u'70272'], [u'98362'], [u'NaN'], [u'NaN']]

How do I delete all those [NaN]s to get:

a = [[u'63764'], [u'63764'], [u'63764'], [u'70272'], [u'98362']]

Thank You

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)

Use math.isnan to check whether the number is NaN:

>>> NaN = float('nan')
>>> import math
>>> math.isnan(1)
False
>>> math.isnan(NaN)
True

with list comprehension:

>>> [xs for xs in a if not any(math.isnan(x) for x in xs)]
[[1], [1], [2], [2], [2], [3], [3]]

UPDATE according to the question edit:

>>> a = [[u'63764'], [u'63764'], [u'63764'], [u'70272'], [u'98362'], [u'NaN'], [u'NaN']]
>>> [x for x in a if x != [u'NaN']]
[[u'63764'], [u'63764'], [u'63764'], [u'70272'], [u'98362']]

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

...