使Python代码流畅无缝连接的链式调用技巧

class Chain:
    def __init__(self):
        self.result = 0
    def add(self, num):
        self.result += num
        return self  # 返回自身以支持链式调用
    def subtract(self, num):
        self.result -= num
        return self
chain = Chain()
result = chain.add(5).subtract(3).add(10).result
print("链式调用结果:", result)  # 输出: 12

# Pandas库中链式调用的应用
import pandas as pd
data = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]})
result = data[data['A'] > 1].iloc[:, 0].sum()
print("Pandas链式调用结果:", result)  # 输出: 5

# 函数式编程中的链式调用
result = list(range(10)).map(lambda x: x * 2).filter(lambda x: x > 5).map(lambda x: x + 1)
print("函数式编程链式调用结果:", result)  # 输出: [7, 9, 11, 13, 15, 17, 19]

class CustomChain:
    def __init__(self):
        self.data = []
    def add(self, item):
        self.data.append(item)
        return self
    def get_result(self):
        return self.data
chain = CustomChain()
result = chain.add(1).add(2).add(3).get_result()
print("定制化链式调用结果:", result)  # 输出: [1, 2, 3]