Python Memory Consumption: Dictionary VS List of Tuples

In this article, we are going to see memory consumption in dictionaries and a list of tuples.

Memory Consumption by dict vs list of tuples

Dictionary occupies much more space than a list of tuples. Even an empty dict occupies much space as compared to a list of tuples.

Example 1: As we can clearly see that there is a huge difference between memory consumption of both the datatypes when both are empty.

Python3

import sys

dict = {}
print(dict)

# We will get size of empty dict
print(sys.getsizeof(dict))

t1 = ()
d = list(t1)
print(d)

# We will get size of empty list of tuples
print(sys.getsizeof(d))

Output:

{}
240
[]
64

Example 2: In this example, therefore 3-4 elements in dict and list of tuples.

Python3

import sys

# for dict
dict = {(1, "G"), (2, "F"), (3, "G")}
print(dict)
print(sys.getsizeof(dict))

# for list of tuples
list1 = (1, 2, 3)
list2 = ("G", "F", "G")
LoT = list(zip(list1, list2))
print(LoT)
print(sys.getsizeof(LoT))

Output:

{(3, 'G'), (1, 'G'), (2, 'F')}
224
[(1, 'G'), (2, 'F'), (3, 'G')]
112

Again we can compare the memory consumption is 224 Bytes in dict whereas 112 for list of tuples.

Example 3: Lets consider 1-100 elements in dict and list of tuples and checkout whats the result.

Python3

import sys

# for dict
dict = {}
for i in range(1, 101):
    dict[i] = i
print(dict)
print(sys.getsizeof(dict))

# for list of tuples
lst = list(range(1, 101))
print(lst)
print(sys.getsizeof(lst))

Output:

{1: 1, 2: 2, 3: 3, 4: 4, 5: 5, 6: 6, 7: 7, 8: 8, 9: 9, 10: 10, 11: 11, 12: 12, 13: 13, 14: 14, 15: 15, 16: 16, 17: 17, 18: 18, 19: 19, 20: 20, 21: 21, 22: 22, 23: 23, 24: 24, 25: 25, 26: 26, 27: 27, 28: 28, 29: 29, 30: 30, 31: 31, 32: 32, 33: 33, 34: 34, 35: 35, 36: 36, 37: 37, 38: 38, 39: 39, 40: 40, 41: 41, 42: 42, 43: 43, 44: 44, 45: 45, 46: 46, 47: 47, 48: 48, 49: 49, 50: 50, 51: 51, 52: 52, 53: 53, 54: 54, 55: 55, 56: 56, 57: 57, 58: 58, 59: 59, 60: 60, 61: 61, 62: 62, 63: 63, 64: 64, 65: 65, 66: 66, 67: 67, 68: 68, 69: 69, 70: 70, 71: 71, 72: 72, 73: 73, 74: 74, 75: 75, 76: 76, 77: 77, 78: 78, 79: 79, 80: 80, 81: 81, 82: 82, 83: 83, 84: 84, 85: 85, 86: 86, 87: 87, 88: 88, 89: 89, 90: 90, 91: 91, 92: 92, 93: 93, 94: 94, 95: 95, 96: 96, 97: 97, 98: 98, 99: 99, 100: 100}

4704

[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100]

1008

For a larger number of elements, we can clearly see that there is no comparison in memory consumption. dict is almost 4.7 times of list of tuples for just 100 elements. If we have lakhs of elements to store, just think about memory taken by a dict.

We have determined the changes in the size of both the objects after the addition of elements which are mentioned below.

Empty	datatypes	memory consumption
64	list of tuples	increases by 64 after every 8 elements
240	dict	increases to 368 from 6th element;1184 from 22nd element; 2280 from 43rd element; 4704 from 86th; 9320 from 171st