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Check if dictionary is empty in Python

Last Updated : 06 Oct, 2024
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Sometimes, we need to check if a particular dictionary is empty or not.

Python 
# initializing empty dictionary
d = {}
print(bool(d))
print(not bool(d))

d = {1: 'Geeks', 2: 'For', 3: 'Geeks'}
print(bool(d))
print(not bool(d))

Output
False
True
True
False

Different Methods to Check if a Dictionary is Empty

Table of Content

Check if a Dictionary is Empty using bool()

The bool function can be used to perform this particular task. As the name suggests it performs the task of converting an object to a boolean value, but here, passing an empty string returns a False, as a failure to convert something that is empty. 

Python 
# initializing empty dictionary
test_dict = {}

# printing original dictionary
print("The original dictionary : " + str(test_dict))

# using bool()
# Check if dictionary is empty
res = not bool(test_dict)

# print result
print("Is dictionary empty ? : " + str(res))

Output
The original dictionary : {}
Is dictionary empty ? : True

Check if a Dictionary is Empty using not operator 

This task can also be performed using the not operator that checks for a dictionary existence, this evaluates to True if any key in the dictionary is not found. 

Python 
# initializing empty dictionary
test_dict = {}

# printing original dictionary
print("The original dictionary : " + str(test_dict))

# using not operator
# Check if dictionary is empty
res = not test_dict

# print result
print("Is dictionary empty ? : " + str(res))

Output
The original dictionary : {}
Is dictionary empty ? : True


Check if a Dictionary is Empty using len()

Here, we are using the Python len() to check if the dictionary is empty or not.

Python 
# initializing empty dictionary
d = {}

# printing original dictionary
print("The original dictionary : " + str(d))

# Check if dictionary is empty using len
res = (len(d) == 0)

# print result
print("Is dictionary empty ? : " + str(res))

Output
The original dictionary : {}
Is dictionary empty ? : True

Check if a Dictionary is Empty using the Equality Operator

Here, we are comparing the dictionary with values with an empty dictionary to check if the dictionary is empty or not.

Python 
# initializing empty dictionary
myDict = {1: 'Hello', 2: 'World' }
test_dict = {}

# printing original dictionary
print("The original dictionary : " + str(myDict))

# using operator
# Check if dictionary is empty
res = test_dict == myDict

# print result
print("Is dictionary empty ? : " + str(res))

Output
The original dictionary : {1: 'Hello', 2: 'World'}
Is dictionary empty ? : False

Check if a Dictionary is Empty using the Using the not operator with the __len__() method:

This approach is similar to the previous one, but it uses the __len__() method instead of the len() function to get the length of the dictionary.

Python 
# Initialize a dictionary with some key-value pairs
myDict = {1: 'Hello', 2: 'World' }

# Print the original dictionary
print("The original dictionary : " + str(myDict))

# Check if the dictionary is empty using the equality operator
res = myDict.__len__()==0

# Print the result
print("Is dictionary empty ? : " + str(res))
#This code is contributed by Edula Vinay Kumar Reddy

Output
The original dictionary : {1: 'Hello', 2: 'World'}
Is dictionary empty ? : False

Using reduce() 

  1. Initialize an empty dictionary test_dict.
  2. Print the original dictionary.
  3. Use the reduce method to check if the dictionary is empty:
  4. Initialize the accumulator to True.
  5. Iterate over each key-value pair in the dictionary using reduce.
  6. Return False as soon as a key-value pair is encountered.
  7. If the iteration completes without finding any key-value pairs, return the initial value of the accumulator,
  8. which is True.
  9. Print the resulting boolean value.
Python 
from functools import reduce

# initializing empty dictionary
test_dict = {}

# printing original dictionary
print("The original dictionary : " + str(test_dict))

# using reduce method to check if dictionary is empty
res = reduce(lambda acc, x: False, test_dict, True)

# print result
print("Is dictionary empty ? : " + str(res))
#This code is contributed by Rayudu.

Output
The original dictionary : {}
Is dictionary empty ? : True

Using heapq:

  1. Import the heapq module.
  2. Initialize an empty list.
  3. Check if the list is empty using the nsmallest() method of the heapq module with k=1 and a custom key
  4. function that returns 0 for all elements.
  5. If the smallest element is not found, then the list is empty.
  6. Return the result.
Python 
import heapq

# initialize empty list
test_list = []
# printing original dictionary
print("The original dictionary : " + str(test_list ))
 
# check if list is empty using heapq
res = not bool(heapq.nsmallest(1, test_list, key=lambda x: 0))

# print result
print("Is list empty? : " + str(res))
#This code is contributed by Rayudu.

Output
The original dictionary : []
Is list empty? : True



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Check if Value Exists in Python Dictionary
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