Find factorial using reduce() Dry Run in PYTHON

Find factorial using reduce() is an interactive PYTHON dry run visualizer from the Special 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.

Find factorial using reduce() Program Code

from functools import reduce

def factorial(n):
    if n < 0:
        return None
    if n == 0:
        return 1
    return reduce(lambda a, b: a * b, range(1, n + 1))

# Test factorial for numbers 0 to 6
for i in range(7):
    print(f"{i}! = {factorial(i)}")

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