r""" Compare two sequences of lines; generate the resulting delta. Each sequence must contain individual single-line strings ending with newlines. Such sequences can be obtained from the `readlines()` method of file-like objects. The delta generated also consists of
(self, a, b)
| 831 | self.charjunk = charjunk |
| 832 | |
| 833 | def compare(self, a, b): |
| 834 | r""" |
| 835 | Compare two sequences of lines; generate the resulting delta. |
| 836 | |
| 837 | Each sequence must contain individual single-line strings ending with |
| 838 | newlines. Such sequences can be obtained from the `readlines()` method |
| 839 | of file-like objects. The delta generated also consists of newline- |
| 840 | terminated strings, ready to be printed as-is via the writelines() |
| 841 | method of a file-like object. |
| 842 | |
| 843 | Example: |
| 844 | |
| 845 | >>> print(''.join(Differ().compare('one\ntwo\nthree\n'.splitlines(True), |
| 846 | ... 'ore\ntree\nemu\n'.splitlines(True))), |
| 847 | ... end="") |
| 848 | - one |
| 849 | ? ^ |
| 850 | + ore |
| 851 | ? ^ |
| 852 | - two |
| 853 | - three |
| 854 | ? - |
| 855 | + tree |
| 856 | + emu |
| 857 | """ |
| 858 | |
| 859 | cruncher = SequenceMatcher(self.linejunk, a, b) |
| 860 | for tag, alo, ahi, blo, bhi in cruncher.get_opcodes(): |
| 861 | if tag == 'replace': |
| 862 | g = self._fancy_replace(a, alo, ahi, b, blo, bhi) |
| 863 | elif tag == 'delete': |
| 864 | g = self._dump('-', a, alo, ahi) |
| 865 | elif tag == 'insert': |
| 866 | g = self._dump('+', b, blo, bhi) |
| 867 | elif tag == 'equal': |
| 868 | g = self._dump(' ', a, alo, ahi) |
| 869 | else: |
| 870 | raise ValueError('unknown tag %r' % (tag,)) |
| 871 | |
| 872 | yield from g |
| 873 | |
| 874 | def _dump(self, tag, x, lo, hi): |
| 875 | """Generate comparison results for a same-tagged range.""" |