Find equal sequence from 10 lines strings

Question

I'm trying find longest common sequence from text file, which contains string lines. Output should be also text file with align lines like in example:

find sequence - efghijk

output file:

abcdefghijklmno     
  dfefghijkrumlp    
 swrefghijkawsfce   
wsveefghijksxl

I'm thinking about use difflib, save lines to list and then compare list[0] and list[1], find longest sequence from this two strings and then difflib(None, sequence, list[2]) etc.

But I have some trouble with coding this and I absolutely dont know how to do the output file.

Thanks for advice, Jan

score 0 · Answer 1 · answered Mar 31 '14 at 13:02

Printing the output is pretty easy. Imagine that you've already got the positions where the longest common substring begins in the strings. For your example it'd be [4, 2, 3, 4]. Now just shift all the strings by max(begins) - begins[i] - it indents the strings correctly.

strings = ("abcdefghijklmno", "dfefghijkrumlp", "swrefghijkawsfce", "wsveefghijksxl")
positions = (4, 2, 3, 4)

maxpos = max(positions)

for i in range(len(strings)):
    print (" " * (maxpos - positions[i])) + strings[i]

Find equal sequence from 10 lines strings

1 Answers1