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This article will show you how to compare two dictionaries in Python.

Comparing two dictionaries in Python using ==the operator

==The operator in Python can be used to determine whether dictionaries are identical.

Here is an example when the same dictionary exists.

dict1 = dict(name="Tom", Vehicle="Benz Car")
dict2 = dict(name="Tom", Vehicle="Benz Car")
dict1 == dict2

Output:

True

Here is an example, when there are different dictionaries −

dict1 = dict(name="John", Vehicle="Benz Car")
dict2 = dict(name="Tom", Vehicle="Benz Car")
dict1 == dict2

Output:

False

You can compare many dictionaries mentioned in the following example,

dict1 = dict(name="John", Vehicle="Benz Car")
dict2 = dict(name="Tom", Vehicle="Benz Car")
dict3 = dict(name="Shona", Vehicle="Alto Car")
dict4 = dict(name="Ruby", Vehicle="Honda Car")
dict1 == dict2 == dict3 == dict4

Output:

False

Writing custom code to compare two dictionaries in Python

Here is how you can write code to compare dictionaries and determine how many pairs are common between the dictionaries. Here are the steps.

• Use fora loop to iterate over each item in one of the dictionaries. Compare each item of this dictionary to the other dictionary based on a shared index.

• If the items are equal, the pair is key:valueplaced into the resulting shared dictionary.

• After iterating through the entire dictionary, calculate the length of the resulting shared dictionary to determine the number of common items between the dictionaries.

Following is an example that demonstrates how to compare two dictionaries in Python.

In this case the dictionaries are identical.

dict1 = dict(name="Tom", Vehicle="Mercedes Car")
dict2 = dict(name="Tom", Vehicle="Mercedes Car")
dict1_len = len(dict1)
dict2_len = len(dict2)
total_dict_count = dict1_len + dict2_len

shared_dict = {}

for i in dict1:
    if (i in dict2) and (dict1[i] == dict2[i]):
        shared_dict[i] = dict1[i]

len_shared_dict = len(shared_dict)

print("The items common between the dictionaries are -", shared_dict)
print("The number of items common between the dictionaries are -", len_shared_dict)

if len_shared_dict == total_dict_count / 2:
    print("The dictionaries are identical")
else:
    print("The dictionaries are non-identical")

Output:

The items common between the dictionaries are - {'name': 'Tom', 'Vehicle': 'Mercedes Car'}
The number of items common between the dictionaries are - 2
The dictionaries are identical

Next, let's try an example where the dictionaries are not identical -

dict1 = dict(name="Tom", Vehicle="Alto Car")
dict2 = dict(name="Tom", Vehicle="Mercedes Car")
dict1_len = len(dict1)
dict2_len = len(dict2)
total_dict_count = dict1_len + dict2_len

shared_dict = {}

for i in dict1:
    if (i in dict2) and (dict1[i] == dict2[i]):
        shared_dict[i] = dict1[i]
len_shared_dict = len(shared_dict)
print("The items common between the dictionaries are -", shared_dict)
print("The number of items common between the dictionaries are -", len_shared_dict)
if len_shared_dict == total_dict_count / 2:
    print("The dictionaries are identical")
else:
    print("The dictionaries are non-identical")

Output:

The items common between the dictionaries are - {'name': 'Tom'}
The number of items common between the dictionaries are - 1
The dictionaries are non-identical