Pyparsing 3.1.2

• Support for Python 3.13.

• Added ieee_float expression to pyparsing.common, which parses float values, plus "NaN", "Inf", "Infinity". PR submitted by Bob Peterson (#538).

• Updated pep8 synonym wrappers for better type checking compatibility. PR submitted by Ricardo Coccioli (#507).

• Fixed empty error message bug, PR submitted by InSync (#534). This should return pyparsing's exception messages to a former, more helpful form. If you have code that parses the exception messages returned by pyparsing, this may require some code changes.

• Added unit tests to test for exception message contents, with enhancement to pyparsing.testing.assertRaisesParseException to accept an expected exception message.

• Updated example select_parser.py to use PEP8 names and added Groups for better retrieval of parsed values from multiple SELECT clauses.

• Added example email_address_parser.py, as suggested by John Byrd (#539).

• Added example directx_x_file_parser.py to parse DirectX template definitions, and generate a Pyparsing parser from a template to parse .x files.

• Some code refactoring to reduce code nesting, PRs submitted by InSync.

• All internal string expressions using '%' string interpolation and str.format() converted to f-strings.

Pyparsing 3.1.1

• Fixed regression in Word(min), reported by Ricardo Coccioli, good catch! (Issue #502)

• Fixed bug in bad exception messages raised by Forward expressions. PR submitted by Kyle Sunden, thanks for your patience and collaboration on this (#493).

• Fixed regression in SkipTo, where ignored expressions were not checked when looking for the target expression. Reported by catcombo, Issue #500.

• Fixed type annotation for enable_packrat, PR submitted by Mike Urbach, thanks! (Issue #498)

• Some general internal code cleanup. (Instigated by Michal Čihař, Issue #488)

Pyparsing 3.1.0

NOTE: In the future release 3.2.0, use of many of the pre-PEP8 methods (such as ParserElement.parseString) will start to raise DeprecationWarnings. 3.2.0 should get released some time later in 2023. I currently plan to completely drop the pre-PEP8 methods in pyparsing 4.0, though we won't see that release until at least late 2023 if not 2024. So there is plenty of time to convert existing parsers to the new function names before the old functions are completely removed. (Big help from Devin J. Pohly in structuring the code to enable this peaceful transition.)

Version 3.2.0 will also discontinue support for Python versions 3.6 and 3.7.

Version 3.1.0 - June, 2023

API CHANGES

• A slight change has been implemented when unquoting a quoted string parsed using the QuotedString class. Formerly, when unquoting and processing whitespace markers such as \t and \n, these substitutions would occur first, and then any additional '' escaping would be done on the resulting string. This would parse "\\n" as "\<newline>". Now escapes and whitespace markers are all processed in a single pass working left to right, so the quoted string "\\n" would get unquoted to "\n" (a backslash followed by "n"). Fixes issue #474 raised by jakeanq, thanks!

• Reworked delimited_list function into the new DelimitedList class. DelimitedList has the same constructor interface as delimited_list, and in this release, delimited_list changes from a function to a synonym for DelimitedList. delimited_list and the older delimitedList method will be deprecated in a future release, in favor of DelimitedList.

• ParserElement.validate() is deprecated. It predates the support for left-recursive parsers, and was prone to false positives (warning that a grammar was invalid when it was in fact valid). It will be removed in a future pyparsing release. In its place, developers should use debugging and analytical tools, such as ParserElement.set_debug() and ParserElement.create_diagram(). (Raised in Issue #444, thanks Andrea Micheli!)

NEW FEATURES AND ENHANCEMENTS

• Optional(expr) may now be written as expr | ""

  This will make this code:

  "{" + Optional(Literal("A") | Literal("a")) + "}"
  

  writable as:

  "{" + (Literal("A") | Literal("a") | "") + "}"
  

  Some related changes implemented as part of this work:

  • Literal("") now internally generates an Empty() (and no longer raises an exception)
  • Empty is now a subclass of Literal

  Suggested by Antony Lee (issue #412), PR (#413) by Devin J. Pohly.

• Added new class method ParserElement.using_each, to simplify code that creates a sequence of Literals, Keywords, or other ParserElement subclasses.

  For instance, to define suppressible punctuation, you would previously write:

  LPAR, RPAR, LBRACE, RBRACE, SEMI = map(Suppress, "(){};")
  

  You can now write:

  LPAR, RPAR, LBRACE, RBRACE, SEMI = Suppress.using_each("(){};")
  

  using_each will also accept optional keyword args, which it will pass through to the class initializer. Here is an expression for single-letter variable names that might be used in an algebraic expression:

  algebra_var = MatchFirst(
      Char.using_each(string.ascii_lowercase, as_keyword=True)
  )
  

• Added new builtin python_quoted_string, which will match any form of single-line or multiline quoted strings defined in Python. (Inspired by discussion with Andreas Schörgenhumer in Issue #421.)

• Extended expr[] notation for repetition of expr to accept a slice, where the slice's stop value indicates a stop_on expression:

  test = "BEGIN aaa bbb ccc END"
  BEGIN, END = Keyword.using_each("BEGIN END".split())
  body_word = Word(alphas)
  
  expr = BEGIN + Group(body_word[...:END]) + END
  # equivalent to
  # expr = BEGIN + Group(ZeroOrMore(body_word, stop_on=END)) + END
  
  print(expr.parse_string(test))
  

  Prints:

  ['BEGIN', ['aaa', 'bbb', 'ccc'], 'END']
  

• Added named field "url" to pyparsing.common.url, returning the entire parsed URL string.

• Added bool embed argument to ParserElement.create_diagram(). When passed as True, the resulting diagram will omit the <DOCTYPE>, <HEAD>, and <BODY> tags so that it can be embedded in other HTML source. (Useful when embedding a call to create_diagram() in a PyScript HTML page.)

• Added recurse argument to ParserElement.set_debug to set the debug flag on an expression and all of its sub-expressions. Requested by multimeric in Issue #399.

• Added '·' (Unicode MIDDLE DOT) to the set of Latin1.identbodychars.

• ParseResults now has a new method deepcopy(), in addition to the current copy() method. copy() only makes a shallow copy - any contained ParseResults are copied as references - changes in the copy will be seen as changes in the original. In many cases, a shallow copy is sufficient, but some applications require a deep copy. deepcopy() makes a deeper copy: any contained ParseResults or other mappings or containers are built with copies from the original, and do not get changed if the original is later changed. Addresses issue #463, reported by Bryn Pickering.

• Added new class property identifier to all Unicode set classes in pyparsing.unicode, using the class's values for cls.identchars and cls.identbodychars. Now Unicode-aware parsers that formerly wrote:

  ppu = pyparsing.unicode
  ident = Word(ppu.Greek.identchars, ppu.Greek.identbodychars)
  

  can now write:

  ident = ppu.Greek.identifier
  # or
  # ident = ppu.Ελληνικά.identifier
  

• Error messages from MatchFirst and Or expressions will try to give more details if one of the alternatives matches better than the others, but still fails. Question raised in Issue #464 by msdemlei, thanks!

BUG FIXES AND GENERAL CHANGES

• Added support for Python 3.12.

• Updated ci.yml permissions to limit default access to source - submitted by Joyce Brum of Google. Thanks so much!

• Updated create_diagram() code to be compatible with railroad-diagrams package version 3.0. Fixes Issue #477 (railroad diagrams generated with black bars), reported by Sam Morley-Short.

• Fixed bug in NotAny, where parse actions on the negated expr were not being run. This could cause NotAny to incorrectly fail if the expr would normally match, but would fail to match if a condition used as a parse action returned False. Fixes Issue #482, raised by byaka, thank you!

• Fixed create_diagram() to accept keyword args, to be passed through to the template.render() method to generate the output HTML (PR submitted by Aussie Schnore, good catch!)

• Fixed bug in python_quoted_string regex.

• Fixed bug when parse actions returned an empty string for an expression that had a results name, that the results name was not saved. That is:

  expr = Literal("X").add_parse_action(lambda tokens: "")("value")
  result = expr.parse_string("X")
  print(result["value"])
  

  would raise a KeyError. Now empty strings will be saved with the associated results name. Raised in Issue #470 by Nicco Kunzmann, thank you.

• Fixed bug in SkipTo where ignore expressions were not properly handled while scanning for the target expression. Issue #475, reported by elkniwt, thanks (this bug has been there for a looooong time!).

• Fixed bug in Word when max=2. Also added performance enhancement when specifying exact argument. Reported in issue #409 by panda-34, nice catch!

• Word arguments are now validated if min and max are both given, that min <= max; raises ValueError if values are invalid.

• Fixed bug in srange, when parsing escaped '/' and '' inside a range set.

• Fixed exception messages for some ParserElements with custom names, which instead showed their contained expression names.

• Fixed bug in pyparsing.common.url, when input URL is not alone on an input line. Fixes Issue #459, reported by David Kennedy.

• Multiple added and corrected type annotations. With much help from Stephen Rosen, thanks!

• Some documentation and error message clarifications on pyparsing's keyword logic, cited by Basil Peace.

• General docstring cleanup for Sphinx doc generation, PRs submitted by Devin J. Pohly. A dirty job, but someone has to do it - much appreciated!

EXAMPLE UPDATES

• Added tag_emitter.py to examples. This example demonstrates how to insert tags into your parsed results that are not part of the original parsed text.

• Added bf.py Brainf*ck parser/executor example. Illustrates using a pyparsing grammar to parse language syntax, and attach executable AST nodes to the parsed results.

• invRegex.py example renamed to inv_regex.py and updated to PEP-8 variable and method naming. PR submitted by Ross J. Duff, thanks!

• Removed examples sparser.py and pymicko.py, since each included its own GPL license in the header. Since this conflicts with pyparsing's MIT license, they were removed from the distribution to avoid confusion among those making use of them in their own projects.

• Updated the lucene_grammar.py example (better support for '*' and '?' wildcards) and corrected the test cases - brought to my attention by Elijah Nicol, good catch!

Pyparsing 3.1.0b2

• Updated create_diagram() code to be compatible with railroad-diagrams package version 3.0. Fixes Issue #477 (railroad diagrams generated with black bars), reported by Sam Morley-Short.

• Fixed bug in NotAny, where parse actions on the negated expr were not being run. This could cause NotAny to incorrectly fail if the expr would normally match, but would fail to match if a condition used as a parse action returned False. Fixes Issue #482, raised by byaka, thank you!

• Fixed create_diagram() to accept keyword args, to be passed through to the template.render() method to generate the output HTML (PR submitted by Aussie Schnore, good catch!)

• Fixed bug in python_quoted_string regex.

• Added examples/bf.py Brainf*ck parser/executor example. Illustrates using a pyparsing grammar to parse language syntax, and attach executable AST nodes to the parsed results.

Pyparsing 3.1.0b1

• Added support for Python 3.12.

• API CHANGE: A slight change has been implemented when unquoting a quoted string parsed using the QuotedString class. Formerly, when unquoting and processing whitespace markers such as \t and \n, these substitutions would occur first, and then any additional '' escaping would be done on the resulting string. This would parse "\n" as "<newline>". Now escapes and whitespace markers are all processed in a single pass working left to right, so the quoted string "\n" would get unquoted to "\n" (a backslash followed by "n"). Fixes issue #474 raised by jakeanq, thanks!

• Added named field "url" to pyparsing.common.url, returning the entire parsed URL string.

• Fixed bug when parse actions returned an empty string for an expression that had a results name, that the results name was not saved. That is:

  expr = Literal("X").add_parse_action(lambda tokens: "")("value")
  result = expr.parse_string("X")
  print(result["value"])
  

  would raise a KeyError. Now empty strings will be saved with the associated results name. Raised in Issue #470 by Nicco Kunzmann, thank you.

• Fixed bug in SkipTo where ignore expressions were not properly handled while scanning for the target expression. Issue #475, reported by elkniwt, thanks (this bug has been there for a looooong time!).

• Updated ci.yml permissions to limit default access to source - submitted by Joyce Brum of Google. Thanks so much!

• Updated the lucene_grammar.py example (better support for '*' and '?' wildcards) and corrected the test cases - brought to my attention by Elijah Nicol, good catch!

Pyparsing 3.1.0a1

NOTE: In the future release 3.2.0, use of many of the pre-PEP8 methods (such as ParserElement.parseString) will start to raise DeprecationWarnings. 3.2.0 should get released some time later in 2023. I currently plan to completely drop the pre-PEP8 methods in pyparsing 4.0, though we won't see that release until at least late 2023 if not 2024. So there is plenty of time to convert existing parsers to the new function names before the old functions are completely removed. (Big help from Devin J. Pohly in structuring the code to enable this peaceful transition.)

Version 3.2.0 will also discontinue support for Python versions 3.6 and 3.7.

• API ENHANCEMENT: Optional(expr) may now be written as expr | ""

  This will make this code:

  "{" + Optional(Literal("A") | Literal("a")) + "}"
  

  writable as:

  "{" + (Literal("A") | Literal("a") | "") + "}"
  

  Some related changes implemented as part of this work:

  • Literal("") now internally generates an Empty() (and no longer raises an exception)
  • Empty is now a subclass of Literal

  Suggested by Antony Lee (issue #412), PR (#413) by Devin J. Pohly.

• Added new class property identifier to all Unicode set classes in pyparsing.unicode, using the class's values for cls.identchars and cls.identbodychars. Now Unicode-aware parsers that formerly wrote:

  ppu = pyparsing.unicode
  ident = Word(ppu.Greek.identchars, ppu.Greek.identbodychars)
  

  can now write:

  ident = ppu.Greek.identifier
  # or
  # ident = ppu.Ελληνικά.identifier
  

• Reworked delimited_list function into the new DelimitedList class. DelimitedList has the same constructor interface as delimited_list, and in this release, delimited_list changes from a function to a synonym for DelimitedList. delimited_list and the older delimitedList method will be deprecated in a future release, in favor of DelimitedList.

• Added new class method ParserElement.using_each, to simplify code that creates a sequence of Literals, Keywords, or other ParserElement subclasses.

  For instance, to define suppressable punctuation, you would previously write:

  LPAR, RPAR, LBRACE, RBRACE, SEMI = map(Suppress, "(){};")
  

  You can now write:

  LPAR, RPAR, LBRACE, RBRACE, SEMI = Suppress.using_each("(){};")
  

  using_each will also accept optional keyword args, which it will pass through to the class initializer. Here is an expression for single-letter variable names that might be used in an algebraic expression:

  algebra_var = MatchFirst(
      Char.using_each(string.ascii_lowercase, as_keyword=True)
  )
  

• Added new builtin python_quoted_string, which will match any form of single-line or multiline quoted strings defined in Python. (Inspired by discussion with Andreas Schörgenhumer in Issue #421.)

• Extended expr[] notation for repetition of expr to accept a slice, where the slice's stop value indicates a stop_on expression:

  test = "BEGIN aaa bbb ccc END"
  BEGIN, END = Keyword.using_each("BEGIN END".split())
  body_word = Word(alphas)
  
  expr = BEGIN + Group(body_word[:END]) + END
  # equivalent to
  # expr = BEGIN + Group(ZeroOrMore(body_word, stop_on=END)) + END
  
  print(expr.parse_string(test))
  

  Prints:

  ['BEGIN', ['aaa', 'bbb', 'ccc'], 'END']
  

• ParserElement.validate() is deprecated. It predates the support for left-recursive parsers, and was prone to false positives (warning that a grammar was invalid when it was in fact valid). It will be removed in a future pyparsing release. In its place, developers should use debugging and analytical tools, such as ParserElement.set_debug() and ParserElement.create_diagram(). (Raised in Issue #444, thanks Andrea Micheli!)

• Added bool embed argument to ParserElement.create_diagram(). When passed as True, the resulting diagram will omit the <DOCTYPE>, <HEAD>, and <BODY> tags so that it can be embedded in other HTML source. (Useful when embedding a call to create_diagram() in a PyScript HTML page.)

• Added recurse argument to ParserElement.set_debug to set the debug flag on an expression and all of its sub-expressions. Requested by multimeric in Issue #399.

• Added '·' (Unicode MIDDLE DOT) to the set of pp.unicode.Latin1.identbodychars.

• Fixed bug in Word when max=2. Also added performance enhancement when specifying exact argument. Reported in issue #409 by panda-34, nice catch!

• Word arguments are now validated if min and max are both given, that min <= max; raises ValueError if values are invalid.

• Fixed bug in srange, when parsing escaped '/' and '' inside a range set.

• Fixed exception messages for some ParserElements with custom names, which instead showed their contained expression names.

• Fixed bug in pyparsing.common.url, when input URL is not alone on an input line. Fixes Issue #459, reported by David Kennedy.

• Multiple added and corrected type annotations. With much help from Stephen Rosen, thanks!

• Some documentation and error message clarifications on pyparsing's keyword logic, cited by Basil Peace.

• General docstring cleanup for Sphinx doc generation, PRs submitted by Devin J. Pohly. A dirty job, but someone has to do it - much appreciated!

• invRegex.py example renamed to inv_regex.py and updated to PEP-8 variable and method naming. PR submitted by Ross J. Duff, thanks!

• Removed examples sparser.py and pymicko.py, since each included its own GPL license in the header. Since this conflicts with pyparsing's MIT license, they were removed from the distribution to avoid confusion among those making use of them in their own projects.

pyparsing 3.0.9

• Added Unicode set BasicMultilingualPlane (may also be referenced as BMP) representing the Basic Multilingual Plane (Unicode characters up to code point 65535). Can be used to parse most language characters, but omits emojis, wingdings, etc. Raised in discussion with Dave Tapley (issue #392).

• To address mypy confusion of pyparsing.Optional and typing.Optional resulting in error: "_SpecialForm" not callable message reported in issue #365, fixed the import in exceptions.py. Nice sleuthing by Iwan Aucamp and Dominic Davis-Foster, thank you! (Removed definitions of OptionalType, DictType, and IterableType and replaced them with typing.Optional, typing.Dict, and typing.Iterable throughout.)

• Fixed typo in jinja2 template for railroad diagrams, thanks for the catch Nioub (issue #388).

• Removed use of deprecated pkg_resources package in railroad diagramming code (issue #391).

• Updated bigquery_view_parser.py example to parse examples at https://cloud.google.com/bigquery/docs/reference/legacy-sql

pyparsing 3.0.8

Version 3.0.8 -

• API CHANGE: modified pyproject.toml to require Python version 3.6.8 or later for pyparsing 3.x. Earlier minor versions of 3.6 fail in evaluating the version_info class (implemented using typing.NamedTuple). If you are using an earlier version of Python 3.6, you will need to use pyparsing 2.4.7.

• Improved pyparsing import time by deferring regex pattern compiles. PR submitted by Anthony Sottile to fix issue #362, thanks!

• Updated build to use flit, PR by Michał Górny, added BUILDING.md doc and removed old Windows build scripts - nice cleanup work!

• More type-hinting added for all arithmetic and logical operator methods in ParserElement. PR from Kazantcev Andrey, thank you.

• Fixed infix_notation's definitions of lpar and rpar, to accept parse expressions such that they do not get suppressed in the parsed results. PR submitted by Philippe Prados, nice work.

• Fixed bug in railroad diagramming with expressions containing Combine elements. Reported by Jeremy White, thanks!

• Added show_groups argument to create_diagram to highlight grouped elements with an unlabeled bounding box.

• Added unicode_denormalizer.py to the examples as a demonstration of how Python's interpreter will accept Unicode characters in identifiers, but normalizes them back to ASCII so that identifiers print and 𝕡𝓻ᵢ𝓃𝘁 and 𝖕𝒓𝗂𝑛ᵗ are all equivalent.

• Removed imports of deprecated sre_constants module for catching exceptions when compiling regular expressions. PR submitted by Serhiy Storchaka, thank you.

pyparsing 3.0.7

• Fixed bug #345, in which delimitedList changed expressions in place using expr.streamline(). Reported by Kim Gräsman, thanks!

• Fixed bug #346, when a string of word characters was passed to WordStart or WordEnd instead of just taking the default value. Originally posted as a question by Parag on StackOverflow, good catch!

• Fixed bug #350, in which White expressions could fail to match due to unintended whitespace-skipping. Reported by Fu Hanxi, thank you!

• Fixed bug #355, when a QuotedString is defined with characters in its quoteChar string containing regex-significant characters such as ., *, ?, [, ], etc.

• Fixed bug in ParserElement.run_tests where comments would be displayed using with_line_numbers.

• Added optional "min" and "max" arguments to delimited_list. PR submitted by Marius, thanks!

• Added new API change note in whats_new_in_pyparsing_3_0_0, regarding a bug fix in the bool() behavior of ParseResults.

  Prior to pyparsing 3.0.x, the ParseResults class implementation of __bool__ would return False if the ParseResults item list was empty, even if it contained named results. In 3.0.0 and later, ParseResults will return True if either the item list is not empty or if the named results dict is not empty.

  # generate an empty ParseResults by parsing a blank string with
  # a ZeroOrMore
  result = Word(alphas)[...].parse_string("")
  print(result.as_list())
  print(result.as_dict())
  print(bool(result))
  
  # add a results name to the result
  result["name"] = "empty result"
  print(result.as_list())
  print(result.as_dict())
  print(bool(result))
  

  Prints:

  []
  {}
  False
  
  []
  {'name': 'empty result'}
  True
  

  In previous versions, the second call to bool() would return False.

• Minor enhancement to Word generation of internal regular expression, to emit consecutive characters in range, such as "ab", as "ab", not "a-b".

• Fixed character ranges for search terms using non-Western characters in booleansearchparser, PR submitted by tc-yu, nice work!

• Additional type annotations on public methods.

pyparsing 3.0.6

• Added suppress_warning() method to individually suppress a warning on a specific ParserElement. Used to refactor original_text_for to preserve internal results names, which, while undocumented, had been adopted by some projects.

• Fix bug when delimited_list was called with a str literal instead of a parse expression.