Python | Initialize a dictionary with only keys from a list

Given a List, the task is to create a dictionary with only keys by using given list as keys.

Let’s see the different methods we can do this task.

Method #1 : By iterating through list

# Python code to initialize a dictionary
# with only keys from a list

# List of keys
keyList = ["Paras", "Jain", "Cyware"]

# initialize dictionary
d = {}

# iterating through the elements of list
for i in keyList:
    d[i] = None

print(d)

Output:

{'Cyware': None, 'Paras': None, 'Jain': None}

Method #2 : Using dictionary comprehension

# Python code to initialize a dictionary
# with only keys from a list

# List of Keys
keyList = ["Paras", "Jain", "Cyware"]

# Using Dictionary comprehension
myDict = {key: None for key in keyList}
print(myDict)

Output:

{'Paras': None, 'Jain': None, 'Cyware': None}

Method #3 : Using zip() function

# Python code to initialize a dictionary
# with only keys from a list

# List of keys
listKeys = ["Paras", "Jain", "Cyware"]

# using zip() function to create a dictionary
# with keys and same length None value
dct = dict(zip(listKeys, [None]*len(listKeys)))

# print dict
print(dct)

Output:

{'Cyware': None, 'Paras': None, 'Jain': None}

Method #4 : Using fromkeys() method

# Python code to initialize a dictionary
# with only keys from a list

# List of keys
Student = ["Paras", "Jain", "Cyware"]

# using fromkeys() method
StudentDict = dict.fromkeys(Student, None)

# printing dictionary
print(StudentDict)

Output:

{'Cyware': None, 'Jain': None, 'Paras': None}