Remove whitespace between strings in a list using Python

Question

I have a list of integer strings to sort. The format is like this:

l= ['17', '23', '35', '79', .....]

I need to convert each numeric string into an integer so that I can sort their numeric value. I have tried the following,

l.sort(key=int)

However, I got

invalid literal for int() with base 10: ' '

I think it is due to the whitespace in between the strings. Is that correct? If so, how do I solve it?

Can you please give an example input that causes this issue? — shuttle87
– shuttle87, Commented Nov 12, 2016 at 7:31
Weird, i try your code it did works, space should not be an issue, check your input list whether it contain something that is not numeric or empty — Skycc
– Skycc, Commented Nov 12, 2016 at 7:48

John Zwinck · Accepted Answer · 2016-11-12 07:58:02Z

1

To remove blank strings from a list:

l = filter(str.strip, l)

Then you can sort as you were.

answered Nov 12, 2016 at 7:33

John Zwinck

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4 Comments

@cdarke: It directly solves the OP's problem. I think you just haven't thought about how.

@cdarke it's not... Blank strings raise the OP's exception and this answer filters those out...

However if you're going to use filter @John I'd avoid the lambda and use str.strip directly.

@LijieZhou: Great. Please note that you can "accept" an answer by clicking the checkmark on the left if it solved your problem.