filter() — Expert Playground

Returns elements from an iterable for which a function returns True

Python Playground

# filter() internals
import dis

def using_filter():
    pass

# Bytecode analysis
dis.dis(using_filter)

# Check if it's truly built-in
import builtins
print(f"\nfilter is builtin: {hasattr(builtins, 'filter')}")
print(f"Type: {type(builtins.filter)}")

Output

Click "Run" to execute your code

Understanding the internal implementation helps optimize hot paths in performance-critical code.

Challenge

Try modifying the code above to explore different behaviors. Can you extend the example to handle a new use case?

View all Expert examples for filter()