SequenceMatcher.get_opcodes
- SequenceMatcher.get_opcodes()
Return list of 5-tuples describing how to turn a into b.
Each tuple is of the form (tag, i1, i2, j1, j2). The first tuple
has i1 == j1 == 0, and remaining tuples have i1 == the i2 from the
tuple preceding it, and likewise for j1 == the previous j2.
The tags are strings, with these meanings:
'replace': a[i1:i2] should be replaced by b[j1:j2]
'delete': a[i1:i2] should be deleted.
Note that j1==j2 in this case.
'insert': b[j1:j2] should be inserted at a[i1:i1].
Note that i1==i2 in this case.
'equal': a[i1:i2] == b[j1:j2]
>>> a = "qabxcd"
>>> b = "abycdf"
>>> s = SequenceMatcher(None, a, b)
>>> for tag, i1, i2, j1, j2 in s.get_opcodes():
... print(("%7s a[%d:%d] (%s) b[%d:%d] (%s)" %
... (tag, i1, i2, a[i1:i2], j1, j2, b[j1:j2])))
delete a[0:1] (q) b[0:0] ()
equal a[1:3] (ab) b[0:2] (ab)
replace a[3:4] (x) b[2:3] (y)
equal a[4:6] (cd) b[3:5] (cd)
insert a[6:6] () b[5:6] (f)© Python Software Foundation. PSF License Version 2 · Official docs ↗
1 Example
>>> a = "qabxcd" >>> b = "abycdf" >>> s = SequenceMatcher(None, a, b) >>> for tag, i1, i2, j1, j2 in s.get_opcodes(): ... print('{:7} a[{}:{}] --> b[{}:{}] {!r:>8} --> {!r}'.format( ... tag, i1, i2, j1, j2, a[i1:i2], b[j1:j2])) delete a[0:1] --> b[0:0] 'q' --> '' equal a[1:3] --> b[0:2] 'ab' --> 'ab' replace a[3:4] --> b[2:3] 'x' --> 'y' equal a[4:6] --> b[3:5] 'cd' --> 'cd' insert a[6:6] --> b[5:6] '' --> 'f'
from the Python docs