unidiff

0.7.5 · active · verified Sun Apr 05

unidiff is a simple Python library for parsing and interacting with unified diff data. It allows developers to extract metadata, file changes, and hunk information from diffs. The current version is 0.7.5, and it maintains an active development status with periodic releases addressing bug fixes and feature enhancements.

Warnings

breaking In unidiff v0.7.0, the way renamed files report their target path changed. `PatchedFile.path` now returns the *target* filename for renamed files. If your code previously relied on another attribute or inferred the target path differently, it might break.
Fix: Update your code to use `PatchedFile.path` for the target filename of renamed files. Review `PatchedFile` attributes for source filename if needed.
gotcha Older versions of unidiff (prior to v0.7.4-0.7.5) had issues parsing git diffs with spaces in filenames or those generated with `--no-prefix`. This could lead to incorrect parsing or errors.
Fix: Upgrade to unidiff v0.7.5 or later to ensure correct parsing of diffs with spaces in filenames and `--no-prefix` headers.
gotcha unidiff might throw `UnidiffParseError: Unexpected hunk found` if the diff input lacks proper filename headers (e.g., `--- a/path/to/file` and `+++ b/path/to/file`). While `difflib.unified_diff()` can produce diffs without these headers, unidiff expects them.
Fix: Ensure that the diff data provided to `PatchSet` includes valid filename headers (e.g., `--- a/old_file.py` and `+++ b/new_file.py`). If processing output from `difflib`, you may need to pre-process it to add these headers or handle the `UnidiffParseError`.
gotcha Handling of binary files was improved in v0.6.0 and v0.7.5. Older versions might not correctly identify or process changes in binary files, or might error if a binary file is the first change in a patch.
Fix: Upgrade to unidiff v0.7.5 to ensure robust handling and identification of binary files within patch sets. Use `PatchedFile.is_binary_file` to check file type.

Install

pip install unidiff Install stable release

Imports

PatchSet
```
from unidiff import PatchSet
```

Quickstart

This quickstart demonstrates how to fetch a diff from a URL and parse it using `PatchSet`. It then iterates through the patched files and their hunks to display added and removed lines. `PatchSet` can also be instantiated from a file-like object or directly from a string.

import urllib.request
from unidiff import PatchSet

# Example: Parse a diff from a GitHub pull request URL
diff_url = 'https://github.com/matiasb/python-unidiff/pull/3.diff'
with urllib.request.urlopen(diff_url) as response:
    diff_data = response.read()
    encoding = response.headers.get_content_charset() or 'utf-8'
    patch = PatchSet(diff_data.decode(encoding))

print(f"Parsed {len(patch)} files in the diff.")
for patched_file in patch:
    print(f"File: {patched_file.path}")
    print(f"  Added: {patched_file.added} lines, Removed: {patched_file.removed} lines")
    for hunk in patched_file:
        for line in hunk:
            if line.is_added:
                print(f"    + {line.value.strip()}")
            elif line.is_removed:
                print(f"    - {line.value.strip()}")

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