Python | Get dictionary keys as a list

Given a dictionary, write a Python program to get the dictionary keys as a list.

Examples:

Input : {1:'a', 2:'b', 3:'c'}
Output : [1, 2, 3]

Input : {'A' : 'ant', 'B' : 'ball'}
Output : ['A', 'B']

Approach #1 : Using dict.keys() [For Python 2.x]

# Python program to get
# dictionary keys as list

def getList(dict):
    return dict.keys()

# Driver program
dict = {1:'Geeks', 2:'for', 3:'geeks'}
print(getList(dict))

Output:

[1, 2, 3]

Approach #2 : Naive approach.

# Python program to get
# dictionary keys as list

def getList(dict):
    list = []
    for key in dict.keys():
        list.append(key)

    return list

# Driver program
dict = {1:'Geeks', 2:'for', 3:'geeks'}
print(getList(dict))

Output:

[1, 2, 3]

Approach #3 : Typecasting to list

# Python program to get
# dictionary keys as list

def getList(dict):

    return list(dict.keys())

# Driver program
dict = {1:'Geeks', 2:'for', 3:'geeks'}
print(getList(dict))

Output:

[1, 2, 3]

Approach #4 : Unpacking with *
Unpacking with * works with any object that is iterable and, since dictionaries return their keys when iterated through, you can easily create a list by using it within a list literal.

# Python program to get
# dictionary keys as list

def getList(dict):

    return [*dict]

# Driver program
dict = {'a': 'Geeks', 'b': 'For', 'c': 'geeks'}
print(getList(dict))

Output:

['c', 'a', 'b']

Approach #5 : Using itemgetter
itemgetter from operator module return a callable object that fetches item from its operand using the operand’s __getitem__() method. This method is then mapped to dict.items() and them typecasted to list.

# Python program to get
# dictionary keys as list
from operator import itemgetter

def getList(dict):

    return list(map(itemgetter(0), dict.items()))

# Driver program
dict = {'a': 'Geeks', 'b': 'For', 'c': 'geeks'}
print(getList(dict))

Output:

['b', 'a', 'c']