Python Dictionary clear()

The clear() method removes all items from the dictionary. 

Syntax:

dict.clear()

Parameters:

The clear() method doesn't take any parameters.

Returns:

The clear() method doesn't return any value.

Parameters:

The clear() method take O(n) time.

Examples:

Input : d = {1: "geeks", 2: "for"}
        d.clear()
Output : d = {}

Error:

As we are not passing any parameters there
is no chance for any error.

Python3

# Python program to demonstrate working of
# dictionary clear()
text = {1: "geeks", 2: "for"}

text.clear()
print('text =', text)

Output:

text = {}

How is it different from assigning {} to a dictionary? Please refer the below code to see the difference. When we assign {} to a dictionary, a new empty dictionary is created and assigned to the reference. But when we do clear on a dictionary reference, the actual dictionary content is removed, so all references referring to the dictionary become empty. 

Python3

# Python code to demonstrate difference
# clear and {}.

text1 = {1: "geeks", 2: "for"}
text2 = text1

# Using clear makes both text1 and text2
# empty.
text1.clear()

print('After removing items using clear()')
print('text1 =', text1)
print('text2 =', text2)

text1 = {1: "one", 2: "two"}
text2 = text1

# This makes only text1 empty.
text1 = {}

print('After removing items by assigning {}')
print('text1 =', text1)
print('text2 =', text2)

Output:

After removing items using clear()
text1 = {}
text2 = {}
After removing items by assigning {}
text1 = {}
text2 = {1: 'one', 2: 'two'}