pyparsing 3.2.0

pyparsing 3.2.0

on Python PyPI

Version 3.2.0 - October, 2024

• Discontinued support for Python 3.6, 3.7, and 3.8. Adopted new Python features from Python versions 3.7-3.9:

  • Updated type annotations to use built-in container types instead of names imported from the typing module (e.g., list[str] vs List[str]).
  • Reworked portions of the packrat cache to leverage insertion-preserving ordering in dicts (including removal of uses of OrderedDict).
  • Changed pdb.set_trace() call in ParserElement.set_break() to breakpoint().
  • Converted typing.NamedTuple to dataclasses.dataclass in railroad diagramming code.
  • Added from __future__ import annotations to clean up some type annotations. (with assistance from ISyncWithFoo, issue #535, thanks for the help!)

• POSSIBLE BREAKING CHANGES

  The following bugfixes may result in subtle changes in the results returned or exceptions raised by pyparsing.

  • Fixed code in ParseElementEnhance subclasses that replaced detailed exception messages raised in contained expressions with a less-specific and less-informative generic exception message and location.

    If your code has conditional logic based on the message content in raised ParseExceptions, this bugfix may require changes in your code.

  • Fixed bug in transform_string() where whitespace in the input string was not properly preserved in the output string.

    If your code uses transform_string, this bugfix may require changes in your code.

  • Fixed bug where an IndexError raised in a parse action was incorrectly handled as an IndexError raised as part of the ParserElement parsing methods, and reraised as a ParseException. Now an IndexError that raises inside a parse action will properly propagate out as an IndexError. (Issue #573, reported by August Karlstedt, thanks!)

    If your code raises IndexErrors in parse actions, this bugfix may require changes in your code.

• FIXES AND NEW FEATURES

  • Added type annotations to remainder of pyparsing package, and added mypy run to tox.ini, so that type annotations are now run as part of pyparsing's CI. Addresses Issue #373, raised by Iwan Aucamp, thanks!

  • Exception message format can now be customized, by overriding ParseBaseException.format_message:

    def custom_exception_message(exc) -> str:
        found_phrase = f", found {exc.found}" if exc.found else ""
        return f"{exc.lineno}:{exc.column} {exc.msg}{found_phrase}"
    
    ParseBaseException.formatted_message = custom_exception_message
    

    (PR #571 submitted by Odysseyas Krystalakos, nice work!)

  • run_tests now detects if an exception is raised in a parse action, and will report it with an enhanced error message, with the exception type, string, and parse action name.

  • QuotedString now handles translation of escaped integer, hex, octal, and Unicode sequences to their corresponding characters.

  • Fixed the displayed output of Regex terms to deduplicate repeated backslashes, for easier reading in debugging, printing, and railroad diagrams.

  • Fixed (or at least reduced) elusive bug when generating railroad diagrams, where some diagram elements were just empty blocks. Fix submitted by RoDuth, thanks a ton!

  • Fixed railroad diagrams that get generated with a parser containing a Regex element defined using a verbose pattern - the pattern gets flattened and comments removed before creating the corresponding diagram element.

  • Defined a more performant regular expression used internally by common_html_entity.

  • Regex instances can now be created using a callable that takes no arguments and just returns a string or a compiled regular expression, so that creating complex regular expression patterns can be deferred until they are actually used for the first time in the parser.

  • Added optional flatten Boolean argument to ParseResults.as_list(), to return the parsed values in a flattened list.

  • Added indent and base_1 arguments to pyparsing.testing.with_line_numbers. When using with_line_numbers inside a parse action, set base_1=False, since the reported loc value is 0-based. indent can be a leading string (typically of spaces or tabs) to indent the numbered string passed to with_line_numbers. Added while working on #557, reported by Bernd Wechner.

• NEW/ENHANCED EXAMPLES

  • Added query syntax to mongodb_query_expression.py with:

    • better support for array fields ("contains", "contains all", "contains any", and "contains none")
    • "like" and "not like" operators to support SQL "%" wildcard matching and "=~" operator to support regex matching
    • text search using "search for"
    • dates and datetimes as query values
    • a[0] style array referencing

  • Added lox_parser.py example, a parser for the Lox language used as a tutorial in Robert Nystrom's "Crafting Interpreters" (http://craftinginterpreters.com/). With helpful corrections from RoDuth.

  • Added complex_chemical_formulas.py example, to add parsing capability for formulas such as "3(C₆H₅OH)₂".

  • Updated tag_emitter.py to use new Tag class, introduced in pyparsing 3.1.3.