PythonのLambda関数について

基本構文

add = lambda x, y: x + y
print(add(3, 5))

引数として利用する

sorted

students = [
    {"name": "John", "age": 15},
    {"name": "Jane", "age": 17},
    {"name": "Dave", "age": 16},
]
sorted_students = sorted(students, key=lambda student: student["age"])
print(sorted_students)

sort

students = [
    {"name": "John", "age": 15},
    {"name": "Jane", "age": 17},
    {"name": "Dave", "age": 16},
]
students.sort(key=lambda student: student["age"])
print(students)

max

items = [
    {"name": "iPhone", "price": 1000},
    {"name": "Samsung Galaxy", "price": 800},
    {"name": "Pixel", "price": 900},
]
most_expensive = max(items, key=lambda item: item["price"])
print(most_expensive)

min

items = [
    {"name": "iPhone", "price": 1000},
    {"name": "Samsung Galaxy", "price": 800},
    {"name": "Pixel", "price": 900},
]
least_expensive = min(items, key=lambda item: item["price"])
print(least_expensive)

map

nums = [1, 2, 3, 4, 5, 6]
doubled = list(map(lambda x: x * 2, nums))
print(doubled)

filter

nums = [1, 2, 3, 4, 5, 6]
even_nums = list(filter(lambda x: x % 2 == 0, nums))
print(even_nums)

tuple_list = [
    (1, 2, 3, False),
    (1, 2, 3, False),
    (1, 2, 3, False),
    (1, 2, 3, True),
]
result = list(filter(lambda x: x[3], tuple_list))
print(result)