list comprehension python dictionary code example

Example 1: create dictionary comprehension python

{key:value for key in iterable}

Example 2: dictionary comprehension python

square_dict = {num: num*num for num in range(1, 11)}

Example 3: python dictionary comprehension

dict1 = {'a': 1, 'b': 2, 'c': 3, 'd': 4, 'e': 5}
# Double each value in the dictionary
double_dict1 = {k:v*2 for (k,v) in dict1.items()}
# double_dict1 = {'e': 10, 'a': 2, 'c': 6, 'b': 4, 'd': 8} <-- new dict

Example 4: types of dict comprehension

# Dictionary Comprehension Types

{j:j*2 for i in range(10)}

#using if 
{j:j*2 for j in range(10) if j%2==0}

#using if and 
{j:j*2 for j in range(10) if j%2==0 and j%3==0}

#using if else
{j:(j*2 if j%2==0 and j%3==0 else 'invalid' )for j in range(10) }

Example 5: dictionary comprehension in python

# dictionary comprehension
# these are a little bit tougher ones than list comprehension

sample_dict = {
    'a': 1,
    'b': 2,
    'c': 3,
    'd': 4,
    'e': 5
}

# making squares of the numbers using  dict comprehension
square_dict = {key:value**2 for key, value in sample_dict.items()}
print(square_dict)

square_dict_even = {key:value**2 for key, value in sample_dict.items() if value % 2 == 0}
print(square_dict_even)

# if you don't have a dictionary and you wanna create a dictionary of a number:number**2
square_without_dict = {num:num**2 for num in range(11)}
print(square_without_dict)