Python - Remove Dictionary Key Words

We are given a dictionary we need to remove the dictionary key words. For example we are given a dictionary d = {'a': 1, 'b': 2} we need to remove the dictionary key words so that the output becomes {'b': 2} . We can use method like del , pop and other methods to do it.

Using del keyword

del keyword is used to remove a specific key-value pair from a dictionary by specifying the key. If the key exists, it will be deleted; otherwise, it raises a KeyError.

d = {'a': 1, 'b': 2}  
# Remove the key-value pair where the key is 'a' from the dictionary
del d['a']  
print(d) 

{'b': 2}

Explanation:

• Dictionary d is initialized with two key-value pairs: 'a': 1 and 'b': 2.
• del keyword is used to remove the key-value pair with key 'a', and the modified dictionary {'b': 2} is printed.

Using pop() method

pop() method removes and returns the value associated with a specified key in a dictionary. If the key is not found, it raises a KeyError unless a default value is provided.

d = {'a': 1, 'b': 2}  
# Remove the key-value pair where the key is 'a' and return its value
d.pop('a')  
print(d)  

{'b': 2}

Explanation:

• pop('a') method removes key-value pair where the key is 'a' from the dictionary d and returns its value (1 in this case).
• Modified dictionary {'b': 2} is then printed as it no longer contains key 'a'

Using popitem()

popitem() method removes and returns the last key-value pair from a dictionary as a tuple. If the dictionary is empty, it raises a KeyError.

d = {'a': 1, 'b': 2}  

# Removes the last key-value pair ('b': 2) from the dictionary
d.popitem()  
print(d)  

{'a': 1}

Explanation:

• popitem() method removes and returns the last key-value pair ('b': 2) from the dictionary d.
• modified dictionary {'a': 1} is printed, which now only contains the key 'a'

Using Dictionary Comprehension

Dictionary comprehension allows you to create a new dictionary by applying an expression to each key-value pair of an existing dictionary.

d = {'a': 1, 'b': 2}  
# Use dictionary comprehension to create a new dictionary excluding the key 'a'
d = {key: value for key, value in d.items() if key != 'a'}  
print(d)  

{'b': 2}

Explanation:

• Dictionary comprehension iterates over the original dictionary d and creates a new dictionary, excluding the key 'a'.
• Modified dictionary, which now only contains the key 'b': 2, is printed.