Python Pointer: How to Get Pointer of a Variable in Python

In this article, we will discuss pointers in Python and how to get the pointer of a variable in Python.

What is Pointer in Python?

A pointer is a variable that stores the address of another variable. Pointers are used to store the memory address of variables in programming languages like C and C++. However, Python does not support pointers in the same way as these languages. In Python, we can use references to achieve similar functionality.

How to Get Pointer of a Variable in Python?

In Python, we cannot directly access the memory address of a variable like we do with pointers in C or C++. However, we can use the built-in id() function to get the memory address of an object in Python.

Using the `id()` function

The id() function returns a unique identifier for an object, which is its memory address in CPython (the standard Python implementation).

Here’s how to use the id() function:

# Define a variable
x = 10

# Get the memory address of the variable
address = id(x)
print(f'The memory address of x is: {address}')

Output:

The memory address of x is: 140712857146368

In this example, we defined a variable x and used the id() function to get its memory address.

Using the `ctypes` Library

If you want to work with pointers more like in C or C++, you can use the ctypes library in Python. The ctypes library allows you to create C-style pointers.

Here’s how to use the ctypes library to get a pointer of a variable:

import ctypes

# Define a variable
x = 10

# Get the pointer of the variable
pointer = ctypes.pointer(ctypes.c_int(x))
print(f'The pointer of x is: {pointer}')
print(f'The value at the pointer is: {pointer.contents.value}')

Output:

The pointer of x is: <LP_c_int(0x7f1e5d0019b0)>
The value at the pointer is: 10

In this example, we used the ctypes library to create a C-style pointer for the variable x.

Conclusion

In this article, we discussed pointers in Python and how to get the pointer of a variable. While Python does not support pointers in the same way as C or C++, we can use the id() function or the ctypes library to achieve similar functionality. Understanding how to work with references and memory addresses in Python is essential for effective programming in the language.