Find common fragments in multiple strings using SequenceMatcher

Question

I would like to find common string between: strings_list = ['PS1 123456 Test', 'PS1 758922 Test', 'PS1 978242 Test']

The following code returns only the first part "PS1 1", I would imagine the result is "PS1 Test". Could you help me, is it possible to obtain using SequenceMatcher? Thank you in advance!

def findCommonStr(strings_list: list) -> str:

        common_str = strings_list[0]

        for i in range(1, n):
            match = SequenceMatcher(None, common_str, strings_list[i]).get_matching_blocks()[0]      
            common_str = common_str[match.b: match.b + match.size]

        common_str = common_str.strip()

        return common_str

Answer 1

This is without SequenceMatcher approach. If all strings follow the same pattern, you can split them into words on whitespaces.

strings_list = ['PS1 123456 Test', 'PS1 758922 Test', 'PS1 978242 Test']

test = []
for string in strings_list:
  print(string.split())
  test.append(string.split())

>>> ['PS1', '123456', 'Test']
['PS1', '758922', 'Test']
['PS1', '978242', 'Test']

Now you can simply do a set intersection to find the common elements. Reference: Python -Intersection of multiple lists?

set(test[0]).intersection(*test[1:])

>>> {'PS1', 'Test'}

# join them to get string
' '.join(set(test[0]).intersection(*test[1:]))

>>> PS1 Test

This would only work if they follow this pattern of separated by white space.

Function:

def findCommonStr(strings_list: list) -> str:

  all_str = []
  for string in strings_list:
    
    all_str.append(string.split())

  return ' '.join(set(all_str[0]).intersection(*all_str[1:]))