python dict comprehension from list code example

Example 1: 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 2: dict comprehension python

# dict comprehension we use same logic, with a difference of key:value pair
# {key:value for i in list}

fruits = ["apple", "banana", "cherry"]
print({f: len(f) for f in fruits})

#output
{'apple': 5, 'banana': 6, 'cherry': 6}

Example 3: 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 4: dict comprehension python

keys=['var1','var2','var3']
my_dict={key:np.zeros(10) for key in keys}