32.5. 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.RPAR
token.LSQB
token.RSQB
token.COLON
token.COMMA
token.SEMI
token.PLUS
token.MINUS
token.STAR
token.SLASH
token.VBAR
token.AMPER
token.LESS
token.GREATER
token.EQUAL
token.DOT
token.PERCENT
token.LBRACE
token.RBRACE
token.EQEQUAL
token.NOTEQUAL
token.LESSEQUAL
token.GREATEREQUAL
token.TILDE
token.CIRCUMFLEX
token.LEFTSHIFT
token.RIGHTSHIFT
token.DOUBLESTAR
token.PLUSEQUAL
token.MINEQUAL
token.STAREQUAL
token.SLASHEQUAL
token.PERCENTEQUAL
token.AMPEREQUAL
token.VBAREQUAL
token.CIRCUMFLEXEQUAL
token.LEFTSHIFTEQUAL
token.RIGHTSHIFTEQUAL
token.DOUBLESTAREQUAL
token.DOUBLESLASH
token.DOUBLESLASHEQUAL
token.AT
token.ATEQUAL
token.RARROW
token.ELLIPSIS
token.OP
token.AWAIT
token.ASYNC
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.

Changed in version 3.5: Added AWAIT and ASYNC tokens. Starting with Python 3.7, “async” and “await” will be tokenized as NAME tokens, and AWAIT and ASYNC will be removed.

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