Python grouping similar patterns using regex

Question

I want to match or with the string I obtain and group the result based on the times or occurs.

My input will be like:

a or b*~c or 27*y or 5*~b

so my output should be:

a, b*~c, 27*y, 5*~b

My code works if there are exactly 3 or, but returns [] otherwise.

I am new to python and I don't understand exactly how the pattern must be given to the compile function.

import re
input = raw_input(" ")

ans = re.compile(r'(.*) or (.*) or (.*) or (.*)')
print re.findall(ans, input)

Simply split your string using str.split('or'). re.split is expected to be slower, — Narendrasingh Sisodia
– Narendrasingh Sisodia, Commented Oct 30, 2015 at 5:46

The6thSense · Accepted Answer · 2015-10-30 05:44:56Z

2

Just do splitting according to the sub-string or

re.split(r' or ', s)

or

re.split(r'\s+or\s+', s)

The6thSense

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answered Oct 30, 2015 at 5:44

Avinash Raj

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Comments

vks · Accepted Answer · 2015-10-30 06:31:53Z

1

You can do a simple split without any use of re.

input = raw_input()
ans = input.split("or")

or

ans = input.split(" or ")

If you want to use findall you can use

x="a or b*~c or 27*y or 5*~b"
print re.findall(r"(?:^|(?<=\bor\b))\s*(.*?)\s*(?=\bor\b|$)",x)

For both * and or use

x="a or b*~c or 27*y or 5*~b"
print [i.split("*") for i in x.split(" or ")]

Output:[['a'], ['b', '~c'], ['27', 'y'], ['5', '~b']]

answered Oct 30, 2015 at 5:44

vks

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And the deference is: First one returns ['foo ', ' bar'] and the second one returns ['foo', 'bar'] (says that the string is foobar).

@vks how can I split both 'or' and '*'? Basically reducing them to list of lists. My answer should be [[a], [b,~c], [27,y], [5,~b]] Thanks