Functions & basics
Reusable building blocks — parameters, returns, scope, and clear function design.
How to Compare Two Implementations with timeit in Python
Measure and compare the execution time of iterative vs recursive factorial functions using the timeit module.
import timeit
def factorial_iterative(n):
result = 1
for i in range(2, n + 1):
result *= i
return result
def factorial_recursive(n):
if n == 0:
return 1
return n * factorial_recursive(n - 1)
if __name__ == "__main__":
n = 10
iterations = 10000
iterative_time = timeit…Write a Recursive Factorial Function in Python
Define a recursive factorial function that handles edge cases and returns the product of all positive integers up to n.
def factorial(n):
"""Return the factorial of n using recursion."""
if n < 0:
raise ValueError("Factorial is not defined for negative numbers")
if n == 0 or n == 1:
return 1
return n * factorial(n - 1)
if __name__ == "__main__":
print(factorial(5))Browse by section
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Functions & basics — Python code examples
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This page collects functions & basics snippets — short, copy-ready Python you can paste into our free online IDE and run without installing anything. Each sample includes a plain-English explanation and the full source code.
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