How To Convert Generator Object To Dictionary In Python

Last Updated : 30 Jan, 2025

We are given a generator object we need to convert that object to dictionary. For example, a = (1, 2, 3), b = ('a', 'b', 'c') we need to convert this to dictionary so that the output should be {1: 'a', 2: 'b', 3: 'c'}.

Using a Generator Expression

A generator expression can be used to generate key-value pairs, which are then passed to the dict() function to create a dictionary. The generator iterates over data, yielding pairs that dict() converts into a dictionary.

Python

a = ((x, x**2) for x in range(5))  # Generator of key-value pairs (x, x^2)

# Convert generator to dictionary
res = dict(a)

print(res)

Output

{0: 0, 1: 1, 2: 4, 3: 9, 4: 16}

Explanation:

Generator expression ((x, x**2) for x in range(5)) generates key-value pairs where the key is x and the value is x**2 for values of x from 0 to 4.
dict(a) function converts the generator into a dictionary resulting in a dictionary with the keys and values generated by the expression, such as {0: 0, 1: 1, 2: 4, 3: 9, 4: 16}

Using zip() and iter()

Using zip(), two iterables (one for keys and one for values) are paired together into key-value tuples and then passing the result to dict() converts these pairs into a dictionary.

Python

a = (1, 2, 3)
b = ('a', 'b', 'c')

# Generator for key-value pairs using zip
gen = zip(a, b)

# Convert to dictionary
res = dict(gen)

print(res)

Output

{1: 'a', 2: 'b', 3: 'c'}

Explanation:

zip(a, b) function pairs elements from the two iterables a and b, creating key-value tuples like (1, 'a'), (2, 'b'), (3, 'c').
dict(gen) converts these key-value pairs into a dictionary, resulting in {1: 'a', 2: 'b', 3: 'c'}.

Using a Dictionary Comprehension

Using a dictionary comprehension you can directly iterate over the generator to construct a dictionary by assigning each key-value pair. It provides a concise way to transform the generator into a dictionary in one step.

Python

a = (1, 2, 3)
b = ('a', 'b', 'c')

# Generator for key-value pairs using zip
gen = zip(a, b)

# Convert to dictionary using dictionary comprehension
res = {key: value for key, value in gen}

print(res)

Output

{1: 'a', 2: 'b', 3: 'c'}

Explanation:

Generator zip(a, b) pairs elements from the two tuples a and b, creating key-value pairs like (1, 'a'), (2, 'b'), (3, 'c').
Dictionary comprehension {key: value for key, value in gen} iterates over these pairs and constructs a dictionary, resulting in {1: 'a', 2: 'b', 3: 'c'}