Find the number present in a line inside a document if there is a string match from a list of strings

Question

I have a list of strings. If any word in the list matches inside a line within a document, I want to get as output the matching word and a number which will be present in the line, mostly after that matching word. The word and number is mostly separated by a space or :

Example from document:

Expedien: 1-21-212-16-26 

My list:

my_list = ['Reference', 'Ref.', 'tramite', 'Expedien']

The numbers inside the line for the matching string can be either separated by - or maybe without. Example: 1-21-22-45 or RE9833

In this case RE9833 should come entirely (not only the number) if a matching word from the list is found inside the line.

How to write a regex in python for this.

Answer 1

Input file:

$cat input_file
Expedien: 1-21-212-16-26 #other garbage
Reference RE9833 #tralala
abc
123
456
Ref.: UV1234
tramite  1234567
Ref.:

Sample:

import re

my_list = ['Reference', 'Ref.', 'tramite', 'Expedien']

#open the file as input
with open('input_file','r') as infile:
  #create an empty dict to store the pairs
  #that we will extract from the file
  res = dict()
  #for each input line
  for line in infile:
    #the only place we will use regex in this code
    #we split the input strings in a list of strings using
    #as separator : if present followed by some spaces
    elems = re.split('(?::)?\s+', line)
    #we test that we have at least 2 elements 
    #if not we continue with the following line
    if len(elems) >= 2 :
      contains = False
      #tmp will store all the keys identfied
      tmp = ''
      #we go through all the strings present in this list of strings
      for elem in elems:
        #when we enter this if we have already found the key and we have the value
        #at this iteration
        if contains:
          #we store it in the dict
          #reset the check and leave this loop
          res.update({tmp : elem})
          contains = False
          break
        #we check if the elem is in my_list
        if elem in my_list:
          #if this is the case
          #we set contains to true and we save the key in tmp
          contains = True
          tmp = elem
  print(res)

output:

python find_list.py
{'tramite': '1234567', 'Reference': 'RE9833', 'Expedien': '1-21-212-16-26', 'Ref.': ''}

Regex demo: https://regex101.com/r/kSmLzW/3/