Python | Size of string in memory

While working with strings, sometimes, we require to get the size of the string, i.e the length of it. But there can be situations in which we require to get the size that the string takes in bytes usually useful in case one is working with files. Let’s discuss certain ways in which this can be performed. 

Method #1 : Using len() + encode() The simplest and initial method that comes to the mind is to convert the string into a byte format and then extract its size. 

Python3

# Python3 code to demonstrate
# getting size of string in bytes
# using encode() + len()

# initializing string
test_string = "geekforgeeks"

# printing original string
print("The original string : " + str(test_string))

# using encode() + len()
# getting size of string in bytes
res = len(test_string.encode('utf-8'))

# print result
print("The length of string in bytes : " + str(res))

Output : 

The original string : geekforgeeks
The length of string in bytes : 12

Method #2 : Using sys.getsizeof() This task can also be performed by one of the system calls, offered by Python as in sys function library, the getsizeof function can get us the size in bytes of desired string. 

Python3

# Python3 code to demonstrate
# getting size of string in bytes
# using sys.getsizeof()
import sys

# initializing string
test_string = "geekforgeeks"

# printing original string
print("The original string : " + str(test_string))

# using sys.getsizeof()
# getting size of string in bytes
res = sys.getsizeof(test_string)

# print result
print("The length of string in bytes : " + str(res))

Output : 

The original string : geekforgeeks
The length of string in bytes : 12

Method #3 :  Using the memoryview function:
To get the number of bytes in a string using a memoryview, you can use the nbytes attribute of the memoryview object. This attribute returns the total size of the memoryview’s data in bytes.

Python3

# Python3 code to demonstrate
# getting size of string in bytes
# using memoryview() + len()

# initializing string
test_string = "geekforgeeks"

# printing original string
print("The original string : " + str(test_string))

# using memoryview()
# getting size of string in bytes
res = memoryview(test_string.encode('utf-8')).nbytes

# print result
print("The length of string in bytes : " + str(res))
#This code is contributed by Edula Vinay Kumar Reddy

Output

The original string : geekforgeeks
The length of string in bytes : 12

METHOD 4:Using array method

APPROACH:

This code first calculates the size of the string in bytes using the len() function and the encode() method. Then, it creates an array of bytes from the string using the array module. Finally, it calculates the size of the array in bytes and prints both the size in bytes using len() and array.

ALGORITHM:

1. Take the input string from the user.
2. Calculate the size of the string in bytes using the len() function and the encode() method.
3. Create an array of bytes from the string using the array module.
4. Calculate the size of the array in bytes by multiplying the itemsize of the array by the length of the array.
5. Print the size of the string in bytes using len() and the size of the array in bytes.

Python3

import array

string = "geekforgeeks"
bytes_size = len(string.encode('utf-8'))

arr = array.array('B', string.encode('utf-8'))
size = arr.itemsize * len(arr)

print(f"The size of the string '{string}' in bytes is {bytes_size} using len() and {size} using array.")

Output

The size of the string 'geekforgeeks' in bytes is 12 using len() and 12 using array.

The overall time complexity of the algorithm is O(n).
The overall space complexity of the algorithm is O(n).