Feature or enhancement
Every match, search, or fullmatch on a pattern with no capturing groups allocates capture-group bookkeeping, then frees it without ever reading it. Group-less patterns are common in validation and scanning code, so this runs often.
Examples:
- Checking the format of millions of records during an import, e.g. re.match(r"\d{4}-\d{2}-\d{2}", value).
- Scanning each log line with re.search(r"ERROR|WARN", line).
- Routers and frameworks testing many small patterns per request.
Proposed change: skip that allocation when a pattern has no capturing groups. Patterns with groups stay untouched, and results are identical.
On a local optimized build, re.match and re.search run 11 to 13 percent faster for group-less patterns on short inputs, with no change for patterns that use groups.
Linked PRs
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Feature or enhancement
Every match, search, or fullmatch on a pattern with no capturing groups allocates capture-group bookkeeping, then frees it without ever reading it. Group-less patterns are common in validation and scanning code, so this runs often.
Examples:
Proposed change: skip that allocation when a pattern has no capturing groups. Patterns with groups stay untouched, and results are identical.
On a local optimized build, re.match and re.search run 11 to 13 percent faster for group-less patterns on short inputs, with no change for patterns that use groups.
Linked PRs