CODEWITHSUNDEEP
pythonregexpython-2.7
Sarchophagi
Sarchophagi

Reputation: 386

Python: How to get string between matches?

I have

FILE = open("file.txt", "r") #long text file
TEXT = FILE.read()

#long identification code with dots (.) and slashes (-)
regex = "process \d\d\d\d\d\d\d\-\d\d\.\d\d\d\d\.\d+\.\d\d\.\d\d\d\d"
SRC = re.findall(regex, TEXT, flags=re.IGNORECASE|re.MULTILINE)

How can I get the text between first char of first occurence SRC[i] and first char of next ocurrence SRC[i+1] and so on? Couldn't find any straight forward satisfatory answer...

MORE INFO EDIT:

pattern = 'process \d{7}\-\d{2}\.\d{4}\.\d+\.\d{2}\.\d{4}'

sample_input = "Process 1234567-89.1234.12431242.12.1234 -  text title and long text description with no assured pattern Process 2234567-89.1234.12431242.12.1234 : chars and more text Process 3234567-89.1234.12431242.12.1234 - more text process 3234567-89.1234.12431242.12.1234 (...)"

sample_output[0] = "Process 1234567-89.1234.12431242.12.1234 -  text title and long text description with no assured pattern "
sample_output[1] = "Process 2234567-89.1234.12431242.12.1234 : chars and more text "
sample_output[2] = "Process 3234567-89.1234.12431242.12.1234 - more text "
sample_output[3] = "process 3234567-89.1234.12431242.12.1234    "

Upvotes: 1

Views: 268

Answers (3)

Federico Piazza
Federico Piazza

Reputation: 30995

You can use this regex:

(Process \d{7}\-\d{2}\.\d{4}\.\d+\.\d{2}\.\d{4}.*?)(?=Process)|(Process \d{7}\-\d{2}\.\d{4}\.\d+\.\d{2}\.\d{4}.*)

Working demo

enter image description here)

Match information

MATCH 1
1.  [0-105] `Process 1234567-89.1234.12431242.12.1234 -  text title and long text description with no assured pattern `
MATCH 2
1.  [105-168]   `Process 2234567-89.1234.12431242.12.1234 : chars and more text `
MATCH 3
1.  [168-221]   `Process 3234567-89.1234.12431242.12.1234 - more text `
MATCH 4
2.  [221-267]   `Process 3234567-89.1234.12431242.12.1234 (...)`

You can use this code:

sample_input = "Process 1234567-89.1234.12431242.12.1234 -  text title and long text description with no assured pattern Process 2234567-89.1234.12431242.12.1234 : chars and more text Process 3234567-89.1234.12431242.12.1234 - more text process 3234567-89.1234.12431242.12.1234 (...)"
m = re.match(r"(Process \d{7}\-\d{2}\.\d{4}\.\d+\.\d{2}\.\d{4}.*?)(?=Process)|(Process \d{7}\-\d{2}\.\d{4}\.\d+\.\d{2}\.\d{4}.*)", sample_input)
m.group(1)       # The first parenthesized subgroup.
m.groups()       # Return a tuple containing all the subgroups of the match, from 1 up to however many groups are in the pattern

Upvotes: 1

dpdwilson
dpdwilson

Reputation: 1007

Suppose you have a string some_str = 'abcARelevant_SubstringAcba' and you want the string between the first A and the second A; i.e. the desired output is 'Relevant_Substring'.

You can find the indices of occurrences of A in some_str with the following line:
inds = [a.start() for a in re.finditer('A', some_str)]

So now inds = [3, 22]. Now some_str[inds[0]+1:inds[1] will contain 'Relevant_Substring'.

This should be extensible to your issue.


EDIT: Here's a concrete example.

Suppose you have a file "file.txt" that contains the following text:

Stuff I don't want.
0
Stuff I do want.
1
More stuff I don't want.

You want to use all digits (0-9) as separators. Therefore, both 0 and 1 above will act as separators. Try the following code:

import re
with open("file.txt", "r") as file:
    data = file.read()
patt = re.compile('[0-9]')
inds = [a.start() for a in re.finditer(patt, data)]
print data[inds[0]+1:inds[1]]

This should print out Stuff I do want.

Upvotes: 1

Padraic Cunningham
Padraic Cunningham

Reputation: 180411

You don't need re to find a string between two chars:

some_str = 'abcARelevant_SubstringAcba'
print some_str.split("A",2)[1]
Relevant_Substring

Upvotes: 0

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