#!/usr/bin/env python3

#

# Copyright 2007 Doug Hellmann.

#

"""SequenceMatcher example

"""

#end_pymotw_header

import difflib

s1 = [1, 2, 3, 5, 6, 4]

s2 = [2, 3, 5, 4, 6, 1]

print('Initial data:')

print('s1 =', s1)

print('s2 =', s2)

print('s1 == s2:', s1 == s2)

print()

matcher = difflib.SequenceMatcher(None, s1, s2)

for tag, i1, i2, j1, j2 in reversed(matcher.get_opcodes()):

if tag == 'delete':

print('Remove {} from positions [{}:{}]'.format(

s1[i1:i2], i1, i2))

print(' before =', s1)

del s1[i1:i2]

elif tag == 'equal':

print('s1[{}:{}] and s2[{}:{}] are the same'.format(

i1, i2, j1, j2))

elif tag == 'insert':

print('Insert {} from s2[{}:{}] into s1 at {}'.format(

s2[j1:j2], j1, j2, i1))

print(' before =', s1)

s1[i1:i2] = s2[j1:j2]

elif tag == 'replace':

print(('Replace {} from s1[{}:{}] '

'with {} from s2[{}:{}]').format(

s1[i1:i2], i1, i2, s2[j1:j2], j1, j2))

print(' before =', s1)

s1[i1:i2] = s2[j1:j2]

print(' after =', s1, '\n')

print('s1 == s2:', s1 == s2)