vscodiff

Python implementation of VS Code's diff algorithm, referenced from the VS Code source code.

Features

• Myers diff algorithm (O(ND) difference)
• Line-level diff with subword refinement
• Timeout-aware computation (set max time per diff)
• LRU cache for repeated diff requests
• Move detection support
• Type-safe — fully typed with py.typed marker

Installation

Recommended — with uv:

uv add vscodiff

Alternative — with pip:

pip install vscodiff

Requires Python ≥ 3.12.

Quick Start

from vscodiff import VSCDiff, DiffOptions

diff = VSCDiff()

# Compute diff between two strings
result = diff.compute_diff("hello\nworld", "hello\nthere\nworld")

for change in result.changes:
    print(f"  original lines {change.original}: {change.inner_changes}")

API

VSCDiff

Main diff entry point. Configure with VSCDiffOptions:

from vscodiff import VSCDiff, VSCDiffOptions, DiffOptions

options = VSCDiffOptions(
    diff_options=DiffOptions(
        ignore_trim_whitespace=True,
        max_computation_time_ms=1000,
        compute_moves=False,
        diff_algorithm="advanced",
    ),
    cache_size=100,
)
diff = VSCDiff(options)
result = diff.compute_diff(original_text, modified_text)

Key Types

Type	Description
VSCDiff	Main diff engine
DocumentDiff	Result: identical, quit_early, changes, moves
DetailedLineRangeMapping	A changed line range with inner char-level diffs
RangeMapping	Character-level diff range
LinesDiff	Raw line diff output (changes + moves + timeout)

License

MIT