lambda — Intermediate Examples
Creates a small anonymous (unnamed) function in a single expression
Lambda in higher-order functions
Using lambda with map, filter, and reduce.
python
# map: transform each element temps_c = [0, 20, 37, 100] temps_f = list(map(lambda c: c * 9/5 + 32, temps_c)) print(f"Fahrenheit: {temps_f}") # filter: keep matching elements numbers = range(1, 21) primes = list(filter( lambda n: n > 1 and all(n % i != 0 for i in range(2, int(n**0.5)+1)), numbers )) print(f"Primes: {primes}") # sorted with complex key people = [("Alice", 30), ("Bob", 25), ("Charlie", 35)] by_age = sorted(people, key=lambda p: p[1]) print(f"By age: {by_age}")
lambda shines as a throwaway function passed to higher-order functions. For anything more than one expression, use def instead.
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