cpython/Doc/lib/libtokenize.tex

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\section{\module{tokenize} ---
Tokenizer for Python source}
\declaremodule{standard}{tokenize}
\modulesynopsis{Lexical scanner for Python source code.}
\moduleauthor{Ka Ping Yee}{}
\sectionauthor{Fred L. Drake, Jr.}{fdrake@acm.org}
The \module{tokenize} module provides a lexical scanner for Python
source code, implemented in Python. The scanner in this module
returns comments as tokens as well, making it useful for implementing
``pretty-printers,'' including colorizers for on-screen displays.
The scanner is exposed by a single function:
\begin{funcdesc}{tokenize}{readline\optional{, tokeneater}}
The \function{tokenize()} function accepts two parameters: one
representing the input stream, and one providing an output mechanism
for \function{tokenize()}.
The first parameter, \var{readline}, must be a callable object which
provides the same interface as the \method{readline()} method of
built-in file objects (see section~\ref{bltin-file-objects}). Each
call to the function should return one line of input as a string.
The second parameter, \var{tokeneater}, must also be a callable
object. It is called with five parameters: the token type, the
token string, a tuple \code{(\var{srow}, \var{scol})} specifying the
row and column where the token begins in the source, a tuple
\code{(\var{erow}, \var{ecol})} giving the ending position of the
token, and the line on which the token was found. The line passed
is the \emph{logical} line; continuation lines are included.
\end{funcdesc}
All constants from the \refmodule{token} module are also exported from
\module{tokenize}, as are two additional token type values that might be
passed to the \var{tokeneater} function by \function{tokenize()}:
\begin{datadesc}{COMMENT}
Token value used to indicate a comment.
\end{datadesc}
\begin{datadesc}{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.
\end{datadesc}