pypi / pyparsing

pyparsing

What changed in pyparsing 3, from its official release notes, upgrade guides and advisories. Sources checked 2026-10-25.

2 breaking1 deprecations5 new APIs and options3 performance1 tooling1 fixes and other

See which of these apply to your code, ranked, in your agent:

npx @unstale/cli init

pyparsing 313 changes

Diagrams may render differently because they no longer rely on recursion using Forward expressions.
3.3.3release notes
Added to pyparsing.common as a generalized parse action that supports expressions extracting date/time fields into results names and validates that the fields represent a valid date and time.
3.3.2release notes

Warning for using deprecated features; it inherits from PyparsingWarning and DeprecationWarning.
3.3.2release notes

A new max argument supports repetition with a large upper bound using multiplication or slicing notation.
3.3.3release notes
Added to pyparsing.common; the expression returns a Python datetime.datetime.
3.3.2release notes
Added to pyparsing.common; the expression returns a Python datetime.datetime.
3.3.2release notes
Warning raised when pyparsing diagnostics are enabled and a diagnostic feature is used.
3.3.2release notes
Base warning for pyparsing-specific warnings, allowing them to be selectively enabled or disabled without affecting warnings from other libraries.
3.3.2release notes

Its recursive implementation was replaced with a shunting-yard algorithm; the release reports significant performance improvements for some complex examples.
3.3.3release notes
Its implementation now manages nesting levels with its own stack, as part of changes intended to improve performance and reduce memory usage.
3.3.3release notes
Performance improvements in ParseResults and core functions yield 10–20% overall performance improvement.
3.3.2release notes

License information is now included in package metadata, following PEP 639.
3.3.1release notes