What the Heck is PyInstanceMethod_Check()

· 283 words · 2 minute read

What the Heck is PyInstanceMethod_Check()? 🔗

Imagine you’ve got a Python object, and you’re like, “Yo, Python! Is this an instance method?” You can’t just ask it straight-up. You need a special tool to figure it out. Enter PyInstanceMethod_Check(), our trusty Sherlock Holmes in the Python C API.

The Basics 🔗

PyInstanceMethod_Check() is a C function that checks if a given object is an instance method. In simpler terms, it’s like checking if that mysterious figure in your living room is actually your pet cat or just a very confused raccoon.

How It’s Used 🔗

Here’s a quick Python-to-C translation to show you how it works:

  1. Include the Header: First, include the Python header in your C code:

    #include <Python.h>

  2. Check the Object: Suppose you have a PyObject *obj, and you want to see if it’s an instance method.

    if (PyInstanceMethod_Check(obj)) {
    printf("This is an instance method!\n");
} else {
    printf("Not an instance method, sorry!\n");
}

How It Works 🔗

Under the hood, PyInstanceMethod_Check() is checking if the object type is a PyInstanceMethod_Type. Think of it like a very picky bouncer at an exclusive club. If you’re not on the list (not an instance method), you’re not getting in.

Here’s a peek into its secret sauce:

#define PyInstanceMethod_Check(op) (Py_TYPE(op) == &PyInstanceMethod_Type)
  • Py_TYPE(op): This gets the type of the object.
  • &PyInstanceMethod_Type: This is the type we’re comparing against, the VIP section for instance methods.

If your object’s type matches PyInstanceMethod_Type, congrats! It’s an instance method.

Why Should You Care? 🔗

If you’re knee-deep in extending Python with C (because you’re hardcore like that), you’ll need to check object types now and then. PyInstanceMethod_Check() is your go-to function for making sure you’re dealing with instance methods and not some imposter.