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author | Martin v. Löwis <martin@v.loewis.de> | 2001-08-16 13:15:00 +0000 |
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committer | Martin v. Löwis <martin@v.loewis.de> | 2001-08-16 13:15:00 +0000 |
commit | 71c736655cb525788096b6f69d189308fd1ac7b3 (patch) | |
tree | 8a1513d4af51235515cd1a955b4261d7b67d739d /Doc/api | |
parent | cf1ee07de3a0a5508466776d8d6cf5ffa34fb8f0 (diff) | |
download | cpython-71c736655cb525788096b6f69d189308fd1ac7b3.tar.gz |
Patch #427190: Implement and use METH_NOARGS and METH_O.
Diffstat (limited to 'Doc/api')
-rw-r--r-- | Doc/api/api.tex | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/Doc/api/api.tex b/Doc/api/api.tex index adcb280258..894e5b6278 100644 --- a/Doc/api/api.tex +++ b/Doc/api/api.tex @@ -5257,6 +5257,68 @@ structure has four fields: \end{tableiii} \end{ctypedesc} +The \var{ml_meth} is a C function pointer. The functions may be of +different types, but they always return \ctype{PyObject*}. If the +function is not of the \ctype{PyCFunction}, the compiler will require +a cast in the method table. Even though \ctype{PyCFunction} defines +the first parameter as \ctype{PyObject*}, it is common that the method +implementation uses a the specific C type of the \var{self} object. + +The flags can have the following values. Only METH_VARARGS and +METH_KEYWORDS can be combined; the others can't. + +\begin{datadesc}{METH_VARARGS} + +This is the typical calling convention, where the methods have the +type \ctype{PyMethodDef}. The function expects two \ctype{PyObject*}. +The first one is the \var{self} object for methods; for module +functions, it has the value given to \cfunction{PyInitModule4} (or +\NULL{} if \cfunction{PyInitModule} was used). The second parameter +(often called \var{args}) is a tuple object representing all +arguments. This parameter is typically processed using +\cfunction{PyArg_ParseTuple}. + +\end{datadesc} + +\begin{datadesc}{METH_KEYWORDS} + +Methods with these flags must be of type +\ctype{PyCFunctionWithKeywords}. The function expects three +parameters: \var{self}, \var{args}, and a dictionary of all the keyword +arguments. The flag is typically combined with METH_VARARGS, and the +parameters are typically processed using +\cfunction{PyArg_ParseTupleAndKeywords}. + +\end{datadesc} + +\begin{datadesc}{METH_NOARGS} + +Methods without parameters don't need to check whether arguments are +given if they are listed with the \code{METH_NOARGS} flag. They need +to be of type \ctype{PyNoArgsFunction}, i.e. they expect a single +\var{self} parameter. + +\end{datadesc} + +\begin{datadesc}{METH_O} + +Methods with a single object argument can be listed with the +\code{METH_O} flag, instead of invoking \cfunction{PyArg_ParseTuple} +with a \code{``O''} argument. They have the type \ctype{PyCFunction}, +with the \var{self} parameter, and a \ctype{PyObject*} parameter +representing the single argument. + +\end{datadesc} + +\begin{datadesc}{METH_OLDARGS} + +This calling convention is deprecated. The method must be of type +\ctype{PyCFunction}. The second argument is \NULL{} if no arguments +are given, a single object if exactly one argument is given, and a +tuple of objects if more than one argument is given. + +\end{datadesc} + \begin{cfuncdesc}{PyObject*}{Py_FindMethod}{PyMethodDef[] table, PyObject *ob, char *name} Return a bound method object for an extension type implemented in C. |