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/Grammar 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.OP
token.AWAIT
token.ASYNC
token.TYPE_IGNORE
token.TYPE_COMMENT
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).