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changedetection.io/changedetectionio/diff.py

98 lines
3.9 KiB

import difflib
from typing import List, Iterator, Union
def same_slicer(lst: List[str], start: int, end: int) -> List[str]:
"""Return a slice of the list, or a single element if start == end."""
return lst[start:end] if start != end else [lst[start]]
def customSequenceMatcher(
before: List[str],
after: List[str],
include_equal: bool = False,
include_removed: bool = True,
include_added: bool = True,
include_replaced: bool = True,
include_change_type_prefix: bool = True
) -> Iterator[List[str]]:
"""
Compare two sequences and yield differences based on specified parameters.
Args:
before (List[str]): Original sequence
after (List[str]): Modified sequence
include_equal (bool): Include unchanged parts
include_removed (bool): Include removed parts
include_added (bool): Include added parts
include_replaced (bool): Include replaced parts
include_change_type_prefix (bool): Add prefixes to indicate change types
Yields:
List[str]: Differences between sequences
"""
cruncher = difflib.SequenceMatcher(isjunk=lambda x: x in " \t", a=before, b=after)
for tag, alo, ahi, blo, bhi in cruncher.get_opcodes():
if include_equal and tag == 'equal':
yield before[alo:ahi]
elif include_removed and tag == 'delete':
prefix = "(removed) " if include_change_type_prefix else ''
yield [f"{prefix}{line}" for line in same_slicer(before, alo, ahi)]
elif include_replaced and tag == 'replace':
prefix_changed = "(changed) " if include_change_type_prefix else ''
prefix_into = "(into) " if include_change_type_prefix else ''
yield [f"{prefix_changed}{line}" for line in same_slicer(before, alo, ahi)] + \
[f"{prefix_into}{line}" for line in same_slicer(after, blo, bhi)]
elif include_added and tag == 'insert':
prefix = "(added) " if include_change_type_prefix else ''
yield [f"{prefix}{line}" for line in same_slicer(after, blo, bhi)]
def render_diff(
previous_version_file_contents: str,
newest_version_file_contents: str,
include_equal: bool = False,
include_removed: bool = True,
include_added: bool = True,
include_replaced: bool = True,
line_feed_sep: str = "\n",
include_change_type_prefix: bool = True,
patch_format: bool = False
) -> str:
"""
Render the difference between two file contents.
Args:
previous_version_file_contents (str): Original file contents
newest_version_file_contents (str): Modified file contents
include_equal (bool): Include unchanged parts
include_removed (bool): Include removed parts
include_added (bool): Include added parts
include_replaced (bool): Include replaced parts
line_feed_sep (str): Separator for lines in output
include_change_type_prefix (bool): Add prefixes to indicate change types
patch_format (bool): Use patch format for output
Returns:
str: Rendered difference
"""
newest_lines = [line.rstrip() for line in newest_version_file_contents.splitlines()]
previous_lines = [line.rstrip() for line in previous_version_file_contents.splitlines()] if previous_version_file_contents else []
if patch_format:
patch = difflib.unified_diff(previous_lines, newest_lines)
return line_feed_sep.join(patch)
rendered_diff = customSequenceMatcher(
before=previous_lines,
after=newest_lines,
include_equal=include_equal,
include_removed=include_removed,
include_added=include_added,
include_replaced=include_replaced,
include_change_type_prefix=include_change_type_prefix
)
def flatten(lst: List[Union[str, List[str]]]) -> str:
return line_feed_sep.join(flatten(x) if isinstance(x, list) else x for x in lst)
return flatten(rendered_diff)