Python enumerate 详解

enumerate(iterable, start=0)

fruits = ['apple', 'banana', 'cherry']

for index, fruit in enumerate(fruits):
    print(f"Index: {index}, Fruit: {fruit}")

Index: 0, Fruit: apple
Index: 1, Fruit: banana
Index: 2, Fruit: cherry

letters = ['a', 'b', 'c', 'd']

for index, letter in enumerate(letters, start=1):
    print(f"Index: {index}, Letter: {letter}")

Index: 1, Letter: a
Index: 2, Letter: b
Index: 3, Letter: c
Index: 4, Letter: d

person = {'name': 'Alice', 'age': 30, 'gender': 'female'}

for key, value in enumerate(person.items()):
    print(f"Index: {key}, Key: {value[0]}, Value: {value[1]}")

Index: 0, Key: name, Value: Alice
Index: 1, Key: age, Value: 30
Index: 2, Key: gender, Value: female

def enumerate_custom(iterable, start=0):
    for i in range(len(iterable)):
        yield start + i, iterable[i]