Get the memory usage of an Object in Python

Get the memory usage of an Object in Python #

Use the sys.getsizeof() method to get the memory usage of an object, e.g. sys.getsizeof(['a', 'b', 'c']). The method takes an object argument and returns the size of the object in bytes. All built-in objects can be passed to the sys.getsizeof() method.

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import sys

print(sys.getsizeof({'name': 'Alice'}))  # 👉️ 232

print(sys.getsizeof(100))  # 👉️ 28

The sys.getsizeof method returns the size of an object in bytes.

The object can be any type of object and all built-in objects return correct results.

The getsizeof method only accounts for the direct memory consumption of the object, not the memory consumption of objects it refers to.

Note that some Python objects like lists and dictionaries may reference other objects and the getsizeof method doesn't account for that.

There is a recursive sizeof recipe in the official docs. It uses getsizeof recursively to find the size of an object and the objects it references.

You can also import the getsizeof method directly instead of importing the entire sys module.

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from sys import getsizeof

print(getsizeof([1, 2, 3]))  # 👉️ 80

print(getsizeof(3.14 ** 10))  # 👉️ 24

The sys.getsizeof() method takes an optional second argument - a default value to return if the object doesn't provide means to retrieve the size.

If no default value is provided and the object's size cannot be calculated, a TypeError is raised.

Here are examples of passing different types of objects to the getsizeof method.

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from sys import getsizeof

# 👇️ list
print(getsizeof([]))  # 👉️ 56

# 👇️ dict
print(getsizeof({}))  # 👉️ 64

# 👇️ int
print(getsizeof(0))  # 👉️ 24

# 👇️ float
print(getsizeof(0.0))  # 👉️ 24

# 👇️ string
print(getsizeof(''))  # 👉️ 49

# 👇️ set
print(getsizeof(set()))  # 👉️ 216

# 👇️ tuple
print(getsizeof(()))  # 👉️ 40

# 👇️ boolean
print(getsizeof(True))  # 👉️ 28

Some objects like lists reserve space for more objects than they contain.