import diff_match_patch as dmp_module
dmp_init = dmp_module.diff_match_patch()
old = '    \"\"\"Rotate matrix 90 degrees clockwise.\"\"\"\n    t = transpose(matrix)\n    # BUG: this is counter-clockwise.\n    return t[::-1]\n'
new = '    \"\"\"Rotate matrix 90 degrees clockwise.\"\"\"\n    t = transpose(matrix)\n    # BUG: this is counter-clockwise.\n    return [row[::-1] for row in t]\n'
diffs = dmp_init.diff_main(old, new)
dmp_init.diff_cleanupSemantic(diffs)
patches = dmp_init.patch_make(old, diffs)
patched, res = dmp_init.patch_apply(patches, old)
print('patched:', repr(patched))