Check key existence using 'in' operator Dry Run in PYTHON

Check key existence using 'in' operator is an interactive PYTHON dry run visualizer from the Dict programs section. Study the source code, then use the execution controls to follow each step, variable update, highlighted line, and console output.

This page provides a browser-based dry run with source-code highlighting, auto-scroll, voice narration controls, and execution output for learning the program step by step.

Check key existence using 'in' operator Program Code

# Check if key exists in dictionary
user = {
    "username": "john_doe",
    "email": "john@example.com",
    "age": 25,
    "is_active": True
}
print("Dictionary:", user)

# Using 'in' operator
print(f"\n'username' in user: {'username' in user}")
print(f"'password' in user: {'password' in user}")

# Using 'not in' operator
print(f"'email' not in user: {'email' not in user}")

# Safe access with condition
key_to_check = "age"
if key_to_check in user:
    print(f"\n{key_to_check} exists with value: {user[key_to_check]}")
else:
    print(f"\n{key_to_check} not found")

# Using get() as alternative
value = user.get("salary", "Not found")
print(f"Using get(): {value}")

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