Python 中的枚举

wufei123 2025-01-05 阅读:56 评论:0

请我喝杯咖啡☕ enumerate() 可以创建一个 iterable，它有一个数字加 1 的 iterable，如下所示： *备注：第一个参数是可迭代的（必需类型：可迭代）。第二个参数是 start(optional-def...

请我喝杯咖啡☕

enumerate() 可以创建一个 iterable，它有一个数字加 1 的 iterable，如下所示：
*备注：

第一个参数是可迭代的（必需类型：可迭代）。
第二个参数是 start(optional-default:0-type:int)。
iterable 不能直接用索引访问，所以使用 list() 通过索引访问它。

PHP

fruits = ["apple", "orange", "banana", "kiwi", "lemon", "mango"]

print(enumerate(iterable=fruits))
print(enumerate(iterable=fruits, start=0))
# <enumerate object at 0x793a2cf15200>

print(list(enumerate(iterable=fruits)))
print(list(enumerate(iterable=fruits, start=0)))
# [(0, 'apple'),
#  (1, 'orange'),
#  (2, 'banana'),
#  (3, 'kiwi'),
#  (4, 'lemon'),
#  (5, 'mango')]

print(list(enumerate(iterable=fruits, start=7)))
# [(7, 'apple'),
#  (8, 'orange'),
#  (9, 'banana'),
#  (10, 'kiwi'),
#  (11, 'lemon'),
#  (12, 'mango')]

print(list(enumerate(iterable=fruits))[0])
print(list(enumerate(iterable=fruits, start=0))[0])
# (0, 'apple')

print(list(enumerate(iterable=fruits, start=7))[0])
# (7, 'apple')

print(enumerate(iterable=fruits)[0])
print(enumerate(iterable=fruits, start=0)[0])
print(enumerate(iterable=fruits, start=7)[0])
# error

i, f = list(enumerate(iterable=fruits))[0]
i, f = list(enumerate(iterable=fruits, start=0))[0]
print(i, f)
# 0 apple

i, f = list(enumerate(iterable=fruits, start=7))[0]
print(i, f)
# 7 apple

for i, f in enumerate(iterable=fruits):
for i, f in enumerate(iterable=fruits, start=0):
    print(i, f)
# 0 apple
# 1 orange
# 2 banana
# 3 kiwi
# 4 lemon
# 5 mango

for i, f in enumerate(iterable=fruits, start=7):
    print(i, f)
# 7 apple
# 8 orange
# 9 banana
# 10 kiwi
# 11 lemon
# 12 mango

PHP

fruits = ["apple", "orange", "banana", "kiwi", "lemon", "mango"]

enum = enumerate

print(list(enum(iterable=enum(iterable=fruits, start=7), start=-3)))
# [(-3, (7, 'apple')),
#  (-2, (8, 'orange')),
#  (-1, (9, 'banana')),
#  (0, (10, 'kiwi')),
#  (1, (11, 'lemon')),
#  (2, (12, 'mango'))]

print(list(enum(iterable=enum(iterable=fruits, start=7), start=-3))[0])
# (-3, (7, 'apple'))

i, jf = list(enum(iterable=enum(iterable=fruits, start=7), start=-3))[0]
print(i, jf)
# -3 (7, 'apple')

i, (j, f) = list(enum(iterable=enum(iterable=fruits, start=7), start=-3))[0]
i, [j, f] = list(enum(iterable=enum(iterable=fruits, start=7), start=-3))[0]
print(i, j, f)
# -3 7 apple

for i, jf in enum(iterable=enum(iterable=fruits, start=7), start=-3):
    print(i, jf)
# -3 (7, 'apple')
# -2 (8, 'orange')
# -1 (9, 'banana')
# 0 (10, 'kiwi')
# 1 (11, 'lemon')
# 2 (12, 'mango')

for i, (j, f) in enum(iterable=enum(iterable=fruits, start=7), start=-3):
for i, [j, f] in enum(iterable=enum(iterable=fruits, start=7), start=-3):
    print(i, j, f)
# -3 7 apple
# -2 8 orange
# -1 9 banana
# 0 10 kiwi
# 1 11 lemon
# 2 12 mango

PHP

fruits = ["Apple", "Orange", "Banana", "Kiwi", "Lemon", "Mango"]

enum = enumerate

print(list(enum(enum(enum(fruits, start=7), start=-3), start=4)))
# [(4, (-3, (7, 'Apple'))),
#  (5, (-2, (8, 'Orange'))),
#  (6, (-1, (9, 'Banana'))),
#  (7, (0, (10, 'Kiwi'))),
#  (8, (1, (11, 'Lemon'))),
#  (9, (2, (12, 'Mango')))]

print(list(enum(enum(enum(fruits, start=7), start=-3), start=4))[0])
# (4, (-3, (7, 'Apple')))

i, jkf = list(enum(enum(enum(fruits, start=7), start=-3), start=4))[0]
print(i, jkf)
# 4 (-3, (7, 'Apple'))

i, (jk, f) = list(enum(enum(enum(fruits, start=7), start=-3), start=4))[0]
i, [jk, f] = list(enum(enum(enum(fruits, start=7), start=-3), start=4))[0]
print(i, jk, f)
# 4 -3 (7, 'Apple')

for i, jkf in enum(enum(enum(fruits, start=7), start=-3), start=4):
    print(i, jkf)
# 4 (-3, (7, 'Apple'))
# 5 (-2, (8, 'Orange'))
# 6 (-1, (9, 'Banana'))
# 7 (0, (10, 'Kiwi'))
# 8 (1, (11, 'Lemon'))
# 9 (2, (12, 'Mango'))

for i, (j, kf) in enum(enum(enum(fruits, start=7), start=-3), start=4):
for i, [j, kf] in enum(enum(enum(fruits, start=7), start=-3), start=4):
    print(i, j, kf)
# 4 -3 (7, 'Apple')
# 5 -2 (8, 'Orange')
# 6 -1 (9, 'Banana')
# 7 0 (10, 'Kiwi')
# 8 1 (11, 'Lemon')
# 9 2 (12, 'Mango')

for i, (j, (k, f)) in enum(enum(enum(fruits, start=7), start=-3), start=4):
for i, [j, [k, f]] in enum(enum(enum(fruits, start=7), start=-3), start=4):
    print(i, j, k, f)
# 4 -3 7 Apple
# 5 -2 8 Orange
# 6 -1 9 Banana
# 7 0 10 Kiwi
# 8 1 11 Lemon
# 9 2 12 Mango