Anonymous vs Named Functions Bytecode comparison

dis_sum_anonymous_function.py

# Summing via Anonymous Function

import dis

dis.dis(lambda x, y: x+y)

# output - using Python v.3.10.2
  1           0 LOAD_FAST                0 (x)
              2 LOAD_FAST                1 (y)
              4 BINARY_ADD
              6 RETURN_VALUE

dis_sum_named_function.py

# Summing via Named Function

import dis

def add(x, y):
    return x + y

dis.dis(add)

# output - using Python v.3.10.2
 2           0 LOAD_FAST                0 (x)
             2 LOAD_FAST                1 (y)
             4 BINARY_ADD
             6 RETURN_VALUE

lambda_decorator.py

@lambda func: (lambda *phrase_input: func(*phrase_input).upper())
def louder(phrase):
  return f"Did you say '{phrase}'?"

louder("fizz, buzz")

# output
"DID YOU SAY 'FIZZ, BUZZ'?"

lambda_factorial_recursive.py

factorial = (lambda f: lambda n: 1 if n == 0 else n * f(f)(n-1))(
  lambda f: lambda n: 1 if n == 0 else n * f(f)(n-1)
)

factorial(6)

# or, anonymously as
(lambda f: lambda n: 1 if n == 0 else n * f(f)(n-1))(lambda f: lambda n: 1 if n == 0 else n * f(f)(n-1))(6)

# output
720

lambda_map_filter_example.py

# maps the lambda over the collection `numbers` returning a list
# containing the remainders of each number divided by 2

list(map(lambda x : x%2, numbers))

# filters through `numbers` returning a list of only numbers
# non-divisible by 2

list(filter(lambda x: x % 2 != 0, numbers))

lambda_multi_expression.py

(lambda x: print("double:", x*2) or print("triple:", x*3) or print("square:", x*x))(5)

# output
double: 10
triple: 15
square: 25

lambda_multi_expression_first_only.py

(lambda x: x*2 or x*x or x+6)(5)

# output
10

lambda_multiple_attribute_sort.py

people = [
  {"name": "Gillian", "age": 25},
  {"name": "Jeffrey", "age": 30},
  {"name": "Jessica", "age": 20},
]

people.sort(key=lambda x: (x["age"], x["name"]))

# output

[{'name': 'Jessica', 'age': 20}, {'name': 'Gillian', 'age': 25}, {'name': 'Jeffrey', 'age': 30}]

lambda_named_decorator.py

@scream := lambda func: (lambda *phrase_input: func(*phrase_input).upper())
def louder(phrase):
  return f"Did you say '{phrase}'?"

@scream
def hello(name):
  return f"Hello {name}. Is it me you're looking for?"

hello("Jeff")

# output
"HELLO JEFF. IS IT ME YOU'RE LOOKING FOR?"

lambda_sort_example.py

d = {1: 4, 2: 2, 3: 3, 4: 1}

sorted(d.items(), key=lambda x: x[1])

# output
[(4, 1), (2, 2), (3, 3), (1, 4)]

lambda_wrapper.py

upper = lambda x: x.upper()

upper((lambda y : y + ",buzzzz")("fizzzz"))

# or joining it all in one anonymous line
(lambda x: x.upper())((lambda y : y + ",buzzzz")("fizzzz"))

# output
'FIZZZZ,BUZZZZ'