Finding how much memory is being used by an object in Python

Memory is frequently set up in a computer system as a series of binary digits, or bits. Each byte is given a unique memory location that may be used to read from or write to the byte's value. Bytes, which can be interpreted as characters, integers, floating-point numbers, or other data kinds, are used to store data in memory. You may measure memory use in Python with the aid of tools like the built-in sys.getsizeof() and asizeof() from pympler.

Method 1: Using Getsizeof() Function

The amount of memory required by an object or data structure may be ascertained with this function. The object whose memory size has to be measured serves as the only argument. Any sort of object, including classes and instances specified by the user, may be passed as argument.

Syntax

sys.getsizeof(*objt_name*)

*objt_name* can take any object - integer, strings, functions, etc.

The function returns the size of the given object in bytes.

Algorithm

• Import the required sys module.

• Create a dictionary with various data types, such as strings, integers, floats, lists, and functions.

• Create a function that takes the integer n as an input and returns a list of integers ranging from 0 to n-1.

• Use sys.getsizeof() to find the size of the methods create_nmbr_list and my_dictn.

• Print the value.

Time Complexity − O(1)

Space Complexity − O(n) where n is the size of the dictionary.

The following example illustrates creating a dictionary that includes a list and a lambda function among other data types. A function that generates a lengthy list of integers using the getsizeof() function.

Example

import sys

# Define a dictionary with various data types
my_dictn = {
   "string": "Tutorials Point",
   "integer": 662,
   "float": 3.14,
   "list": [12, 22, 32, 42, 52],
   "function": lambda x: x ** 2
}

# Define a function that creates list of integers
def create_nmbr_list(n):
   return [i for i in range(n)]

# Measure the size of the dictionary and function using sys.getsizeof()
print("Size of dictionary using sys.getsizeof(): ", sys.getsizeof(my_dictn))
print("Size of function using sys.getsizeof(): ", sys.getsizeof(create_nmbr_list))

Output

Size of dictionary using sys.getsizeof():  232
Size of function using sys.getsizeof():  144

Note − The size of the items in memory might change depending on a variety of factors, including the amount of memory presently being utilised by other programmes or the operating system.

Method 2: Using Asizeof( ) Function

This function is provided by the Pympler package and used for memory profiling and optimization. Unlike the built-in getsizeof() function, asizeof() takes into account the memory usage of all the objects referenced by the target object.

Syntax

asizeof(*object_*)

*object_* can take any object - integers, strings, functions, boolean, etc

The function returns the size of the given object and its references in bytes.

Algorithm

• Import the required pympler.asizeof() module.

• Create a dictionary called my_dict2 with different data types.

• Create the function to produce a list of integers.

• My_dict2 and create_int_list's sizes can be recorded, using the asizeof function.

• Using the variables dictn_size_pympler and fnct_size_pympler, print the sizes of my_dict2 and create_int_list.

Time Complexity − O(1)

Space Complexity − O(n) where n is the size of the dictionary.

The following program illustrates a dictionary with lambda function and other data types using asizeof function to find the memory used by the object.

Example

from pympler.asizeof import asizeof

# Define a dictionary with various data types
my_dict2 = {
   "string": "Hello Viewers",
   "integer": 42,
   "float": 3.14,
   "list": [1, 2, 3, 4, 5],
   "set": {10, 20, 30, 40, 50},
   "boolean": True,
   "function": lambda x: x ** 2,
}

# Define a function that creates a large list of integers
def create_int_list(i):
   return [x for x in range(i)]

# Measure the size of the dictionary and function using pympler.asizeof()
dictn_size_pympler = asizeof(my_dict2)
fnct_size_pympler = asizeof(create_int_list)

# Print the results
print("Size of dictionary using pympler.asizeof: ", dictn_size_pympler)
print("Size of function using pympler.asizeof: ", fnct_size_pympler)

Output

Size of dictionary using pympler.asizeof:  384
Size of function using pympler.asizeof:  152

Conclusion

Sys.getsizeof() just returns the size of the item itself, whereas asizeof() returns the size of the object plus every object it references. As a result, asizeof() can show the memory utilisation of an object more clearly.

While sys.getsizeof() just returns the size of the object itself, asizeof() returns the size of every module that the programme has imported and utilised. Depending on the version of Python being used, sys.getsizeof() may react differently.