How to split strings by only the first special character that's within the string?

Question

I'd like to split the below string by only the first equal sign in that string

String:

 s= 'ButtonParams=U3ViamVjdCxFbWFpbA=='

Desired_String:

 s= ['ButtonParams','U3ViamVjdCxFbWFpbA==']

When I do s.split("="), I get the following, which is what I do not want:

s.split("=")
['ButtonParams', 'U3ViamVjdCxFbWFpbA', '', '']

I need to run this function across a list of strings where this is the case, so scalability is important here.

Have you read the documentation for `split()`? – martineau Dec 28 '14 at 19:42 — martineau, Dec 28 '14 at 19:42
Hey but why've you added [tag:regex] – Bhargav Rao Dec 28 '14 at 19:52 — Bhargav Rao, Dec 28 '14 at 19:52

score 8 · Accepted Answer · answered Dec 28 '14 at 19:41

8

split accepts an optional "maxsplit" parameter: if you set it to 1 it will split on the first = character it finds and return the remainder of the string:

>>> s.split('=', 1)
['ButtonParams', 'U3ViamVjdCxFbWFpbA==']

answered Dec 28 '14 at 19:41

Alex Riley

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Bhargav Rao · Answer 2 · 2014-12-28T20:16:24.597

3

s.split("=", maxsplit=1) is the best but

import re
print (re.split('=',s,1))

The output is

['ButtonParams', 'U3ViamVjdCxFbWFpbA==']

As you have tagged regex

A little deviation from the post

If the expected output was ['ButtonParams', 'U3ViamVjdCxFbWFpbA'] then you can have the following liscos (list comprehensions)

[i for i in s.split('=') if i is not '']
[i for i in s.split('=') if i ] (Contributed by Adam Smith)

edited Dec 28 '14 at 20:16

answered Dec 28 '14 at 19:42

Bhargav Rao

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in desired output `U3ViamVjdCxFbWFpbA` has `==` at end – lolbas Dec 28 '14 at 19:44
1

@lolbas Check the edit. – Bhargav Rao Dec 28 '14 at 19:48
@AdamSmith That won't work out as the OP expected something else. Check the edit. :P – Bhargav Rao Dec 28 '14 at 19:49
no reason at all to use regex here. I liked your other answer better, even if it wasn't the same expected output! :) – Adam Smith Dec 28 '14 at 20:01
@AdamSmith Thanks for the review. Check if this answer suits well – Bhargav Rao Dec 28 '14 at 20:16

score 1 · Answer 3 · answered Dec 28 '14 at 19:42

1

str.split accepts an optional argument maxsplit which determines how many splits (maximally) to make, e.g.:

"ButtonParams=U3ViamVjdCxFbWFpbA==".split("=", maxsplit=1)
# ['ButtonParams', 'U3ViamVjdCxFbWFpbA==']

answered Dec 28 '14 at 19:42

Adam Smith

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How to split strings by only the first special character that's within the string?

3 Answers3