Python Dictionary fromkeys() method

Python Dictionary fromkeys() method

The dictionary.fromkeys() method in Python creates a new dictionary from the given sequence of elements and returns a dictionary with the specified keys and values.

Syntax

dictionary.fromkeys(sequence[, value])

Parameter

sequence- This parameter represents the sequence of elements which is to be used as keys for the new dictionary.

value(optional)- This argument signifies the value which is set for each element of the dictionary.

Return

This method returns a dictionary with the specified keys and values.

Example 1

 # Python program explaining
 # the dictionary.fromkeys() method
 dictionary={"banana": "apple",
   "orange": "mango",
   "grapes": 5
 }
 # initializing the sequence
 sequence = ('Monday', 'Tuesday', 'Wednesday')
 # initializing the key
 key = 1
 # creating a new dictionary from the given sequence of elements
 dict = dictionary.fromkeys(sequence, key)
 # returning a dictionary with the specified keys and values.
 print(dict) 

Output

{'Tuesday': 1, 'Monday': 1, 'Wednesday': 1}

Example 2

 # Python program explaining
 # the dictionary.fromkeys() method
 # initializing sequence  
 vowels = { 'a', 'e', 'i', 'o', 'u' } 
 # using fromkeys() to convert sequence to dict  
 # initializing with None 
 dictionary = dict.fromkeys(vowels) 
 # Printing created dict 
 print ("The newly created dict with no values = " + str(dictionary)) 
 # using fromkeys() to convert vowels to dict  
 # initializing with 9 
 dictionary2 = dict.fromkeys(vowels, 9) 
 # Printing the dict 
 print ("New created dict with 9 as its value = " + str(dictionary2)) 

Output

The newly created dict with no values = {'e': None, 'i': None, 'u': None, 'o': None, 'a': None}
New created dict with 9 as its value = {'e': 9, 'i': 9, 'u': 9, 'o': 9, 'a': 9}