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How do I call an object's method from C?
Python Questions and Answers
(Continued from previous question...)
How do I call an object's method from C?
The PyObject_CallMethod() function can be used to call an arbitrary method of an object. The parameters are the object, the name of the method to call, a format string like that used with Py_BuildValue(), and the argument values:
PyObject *
PyObject_CallMethod(PyObject *object, char *method_name,
char *arg_format, ...);
This works for any object that has methods -- whether built-in or user-defined. You are responsible for eventually Py_DECREF'ing the return value.
To call, e.g., a file object's "seek" method with arguments 10, 0 (assuming the file object pointer is "f"):
res = PyObject_CallMethod(f, "seek", "(ii)", 10, 0);
if (res == NULL) {
... an exception occurred ...
}
else {
Py_DECREF(res);
}
Note that since PyObject_CallObject() always wants a tuple for the argument list, to call a function without arguments, pass "()" for the format, and to call a function with one argument, surround the argument in parentheses, e.g. "(i)".
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