对象索引魔法方法

BrightXiong

# !/usr/bin/python3
# -*- coding: utf-8 -*-
# @Time   : 2023/2/20 21:48
# @Author : xiongming
# @File   : duixiang-suoyin.py
# @Desc   : 对象索引魔法方法

class C:
    def __getitem__(self, index):
        print(index)

c = C()
print(c[2])
c[2:8]
s = "I love FishC"
print(s[2:6])
print(s[slice(2, 6)])

print(s[7:])
print(s[slice(7, None)])

print(s[::4])
print(s[slice(None, None, 4)])

print("-----分隔符-----")

class D:
    def __init__(self, data):
        self.data = data
    def __getitem__(self, index):
        return self.data[index]
    def __setitem__(self, index, value):
        self.data[index] = value

d = D([1, 2, 3, 4, 5])

print(d[1])
d[1] = 11
print(d[1])
d[2:4] = [8, 7]
print(d[:])

class E:
    def __init__(self, data):
        self.data = data
    def __getitem__(self, index):
        return self.data[index] * 2

e = E([1, 2, 3, 4, 5])
for i in e:
    print(i, end=' ')

print()

# 迭代器魔法方法
x = [1, 1, 2, 3, 5]
dir(x)
print("-----分隔符-----")
_ = iter(x)
while True:
    try:
        i = _.__next__()
    except StopIteration:
        break
    print(i, end=' ')

print()

# 创造迭代器对象

class Double:
    def __init__(self, start, stop):
        self.value = start - 1
        self.stop = stop
    def __iter__(self):
        return self
    def __next__(self):
        if self.value == self.stop:
            raise StopIteration
        self.value += 1
        return self.value * 2

d = Double(1, 5)
for i in d:
    print(i, end=' ')