Skip to main content

A wrapper around the stdlib `tokenize` which roundtrips.

Project description

build status pre-commit.ci status

tokenize-rt

The stdlib tokenize module does not properly roundtrip. This wrapper around the stdlib provides two additional tokens ESCAPED_NL and UNIMPORTANT_WS, and a Token data type. Use src_to_tokens and tokens_to_src to roundtrip.

This library is useful if you're writing a refactoring tool based on the python tokenization.

Installation

pip install tokenize-rt

Usage

datastructures

tokenize_rt.Offset(line=None, utf8_byte_offset=None)

A token offset, useful as a key when cross referencing the ast and the tokenized source.

tokenize_rt.Token(name, src, line=None, utf8_byte_offset=None)

Construct a token

  • name: one of the token names listed in token.tok_name or ESCAPED_NL or UNIMPORTANT_WS
  • src: token's source as text
  • line: the line number that this token appears on.
  • utf8_byte_offset: the utf8 byte offset that this token appears on in the line.

tokenize_rt.Token.offset

Retrieves an Offset for this token.

converting to and from Token representations

tokenize_rt.src_to_tokens(text: str) -> List[Token]

tokenize_rt.tokens_to_src(Iterable[Token]) -> str

additional tokens added by tokenize-rt

tokenize_rt.ESCAPED_NL

tokenize_rt.UNIMPORTANT_WS

helpers

tokenize_rt.NON_CODING_TOKENS

A frozenset containing tokens which may appear between others while not affecting control flow or code:

  • COMMENT
  • ESCAPED_NL
  • NL
  • UNIMPORTANT_WS

tokenize_rt.parse_string_literal(text: str) -> Tuple[str, str]

parse a string literal into its prefix and string content

>>> parse_string_literal('f"foo"')
('f', '"foo"')

tokenize_rt.reversed_enumerate(Sequence[Token]) -> Iterator[Tuple[int, Token]]

yields (index, token) pairs. Useful for rewriting source.

tokenize_rt.rfind_string_parts(Sequence[Token], i) -> Tuple[int, ...]

find the indices of the string parts of a (joined) string literal

  • i should start at the end of the string literal
  • returns () (an empty tuple) for things which are not string literals
>>> tokens = src_to_tokens('"foo" "bar".capitalize()')
>>> rfind_string_parts(tokens, 2)
(0, 2)
>>> tokens = src_to_tokens('("foo" "bar").capitalize()')
>>> rfind_string_parts(tokens, 4)
(1, 3)

Differences from tokenize

  • tokenize-rt adds ESCAPED_NL for a backslash-escaped newline "token"
  • tokenize-rt adds UNIMPORTANT_WS for whitespace (discarded in tokenize)
  • tokenize-rt normalizes string prefixes, even if they are not parsed -- for instance, this means you'll see Token('STRING', "f'foo'", ...) even in python 2.
  • tokenize-rt normalizes python 2 long literals (4l / 4L) and octal literals (0755) in python 3 (for easier rewriting of python 2 code while running python 3).

Sample usage

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

tokenize_rt-5.2.0.tar.gz (5.3 kB view hashes)

Uploaded Source

Built Distribution

tokenize_rt-5.2.0-py2.py3-none-any.whl (5.8 kB view hashes)

Uploaded Python 2 Python 3

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page