# `token` — Constants used with Python parse trees

Source code: Lib/token.py

This module provides constants which represent the numeric values of leaf nodes of the parse tree (terminal tokens). Refer to the file `Grammar/Tokens` in the Python distribution for the definitions of the names in the context of the language grammar. The specific numeric values which the names map to may change between Python versions.

The module also provides a mapping from numeric codes to names and some functions. The functions mirror definitions in the Python C header files.

token.tok_name

  Dictionary mapping the numeric values of the constants defined in this module back to name strings, allowing more human-readable representation of parse trees to be generated.

token.ISTERMINAL(x)

  Return `True` for terminal token values.

token.ISNONTERMINAL(x)

  Return `True` for non-terminal token values.

token.ISEOF(x)

  Return `True` if x is the marker indicating the end of input.

The token constants are:

token.ENDMARKER

token.NAME

token.NUMBER

token.STRING

token.NEWLINE

token.INDENT

token.DEDENT

token.LPAR

  Token value for `"("`.

token.RPAR

  Token value for `")"`.

token.LSQB

  Token value for `"["`.

token.RSQB

  Token value for `"]"`.

token.COLON

  Token value for `":"`.

token.COMMA

  Token value for `","`.

token.SEMI

  Token value for `";"`.

token.PLUS

  Token value for `"+"`.

token.MINUS

  Token value for `"-"`.

token.STAR

  Token value for `"*"`.

token.SLASH

  Token value for `"/"`.

token.VBAR

  Token value for `"|"`.

token.AMPER

  Token value for `"&"`.

token.LESS

  Token value for `"<"`.

token.GREATER

  Token value for `">"`.

token.EQUAL

  Token value for `"="`.

token.DOT

  Token value for `"."`.

token.PERCENT

  Token value for `"%"`.

token.LBRACE

  Token value for `"{"`.

token.RBRACE

  Token value for `"}"`.

token.EQEQUAL

  Token value for `"=="`.

token.NOTEQUAL

  Token value for `"!="`.

token.LESSEQUAL

  Token value for `"<="`.

token.GREATEREQUAL

  Token value for `">="`.

token.TILDE

  Token value for `"~"`.

token.CIRCUMFLEX

  Token value for `"^"`.

token.LEFTSHIFT

  Token value for `"<<"`.

token.RIGHTSHIFT

  Token value for `">>"`.

token.DOUBLESTAR

  Token value for `"**"`.

token.PLUSEQUAL

  Token value for `"+="`.

token.MINEQUAL

  Token value for `"-="`.

token.STAREQUAL

  Token value for `"*="`.

token.SLASHEQUAL

  Token value for `"/="`.

token.PERCENTEQUAL

  Token value for `"%="`.

token.AMPEREQUAL

  Token value for `"&="`.

token.VBAREQUAL

  Token value for `"|="`.

token.CIRCUMFLEXEQUAL

  Token value for `"^="`.

token.LEFTSHIFTEQUAL

  Token value for `"<<="`.

token.RIGHTSHIFTEQUAL

  Token value for `">>="`.

token.DOUBLESTAREQUAL

  Token value for `"**="`.

token.DOUBLESLASH

  Token value for `"//"`.

token.DOUBLESLASHEQUAL

  Token value for `"//="`.

token.AT

  Token value for `"@"`.

token.ATEQUAL

  Token value for `"@="`.

token.RARROW

  Token value for `"->"`.

token.ELLIPSIS

  Token value for `"..."`.

token.COLONEQUAL

  Token value for `":="`.

token.EXCLAMATION

  Token value for `"!"`.

token.OP

token.AWAIT

token.ASYNC

token.TYPE_IGNORE

token.TYPE_COMMENT

token.SOFT_KEYWORD

token.FSTRING_START

token.FSTRING_MIDDLE

token.FSTRING_END

token.COMMENT

token.NL

token.ERRORTOKEN

token.N_TOKENS

token.NT_OFFSET

The following token type values aren’t used by the C tokenizer but are needed for the `tokenize` module.

token.COMMENT

  Token value used to indicate a comment.

token.NL

  Token value used to indicate a non-terminating newline. The `NEWLINE` token indicates the end of a logical line of Python code; `NL` tokens are generated when a logical line of code is continued over multiple physical lines.

token.ENCODING

  Token value that indicates the encoding used to decode the source bytes into text. The first token returned by `tokenize.tokenize()` will always be an `ENCODING` token.

token.TYPE_COMMENT

  Token value indicating that a type comment was recognized. Such tokens are only produced when `ast.parse()` is invoked with `type_comments=True`.

Changed in version 3.5: Added `AWAIT` and `ASYNC` tokens.

Changed in version 3.7: Added `COMMENT`, `NL` and `ENCODING` tokens.

Changed in version 3.7: Removed `AWAIT` and `ASYNC` tokens. “async” and “await” are now tokenized as `NAME` tokens.

Changed in version 3.8: Added `TYPE_COMMENT`, `TYPE_IGNORE`, `COLONEQUAL`. Added `AWAIT` and `ASYNC` tokens back (they’re needed to support parsing older Python versions for `ast.parse()` with `feature_version` set to 6 or lower).