Python3 Att Dictionary In Html

📅 2026-06-20 | 📂 Python3

Python3 Dictionary 'in' Operator

Description

The Python dictionary in operator is used to check if a key exists in the dictionary. If the key is in the dictionary dict, it returns true; otherwise, it returns false.

The not in operator works in the opposite way. If the key is in the dictionary dict, it returns false; otherwise, it returns true.

Syntax

Syntax for the in operator:

key in dict

Parameters

key -- The key to look for in the dictionary.

Return Value

Returns true if the key is in the dictionary, otherwise returns false.

Example

The following example demonstrates the usage of the in operator in a dictionary:

Example (Python 3.0+)

#!/usr/bin/python3

thisdict = {
  'Name': '',
  'Age': 7
}

# Check if key 'Age' exists
if 'Age' in thisdict:
    print("Key 'Age' exists")
else:
    print("Key 'Age' does not exist")

# Check if key 'Sex' exists
if 'Sex' in thisdict:
    print("Key 'Sex' exists")
else:
    print("Key 'Sex' does not exist")

# not in
# Check if key 'Age' does not exist
if 'Age' not in thisdict:
    print("Key 'Age' does not exist")
else:
    print("Key 'Age' exists")

The output of the above example is:

Key 'Age' exists
Key 'Sex' does not exist
Key 'Age' exists

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