Reference library

Lists & loops

Iterate, transform, and combine sequences with readable loop patterns.

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Lists & loops easy

How to Validate List Data in Python

A beginner-friendly validation helper that checks if data is a list, enforces minimum length, and optionally verifies item types with clear error messages.

validation lists loops
Python 
def validate_data(data, expected_types=None, min_length=1):
    """Validate that data is a non-empty list and optionally check item types."""
    if not isinstance(data, list):
        return False, f"Expected a list, got {type(data).__name__}"
    
    if len(data) < min_length:
        return False, f"List must have…
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Lists & loops — Python code examples

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