如何修改Python函数，实现无重复代码查找最长/最短字符串？

方法1：提取通用核心逻辑，传入比较规则 #

把重复的遍历、更新逻辑抽成一个通用函数，将判断条件作为参数传入，彻底避免代码复制：

def _find_extreme(words, compare_func):
    N = len(words)
    if N == 0:  # 增加空数组判断，避免索引越界
        return None
    extreme = words[0]
    i = 1
    while i < N:
        if compare_func(len(extreme), len(words[i])):
            extreme = words[i]
        i += 1
    return extreme

def find_shortest(words):
    return _find_extreme(words, lambda a, b: a >= b)

def find_longest(words):
    return _find_extreme(words, lambda a, b: a <= b)

如果觉得lambda不够直观，也可以用operator模块的内置比较函数替代：

import operator

def find_shortest(words):
    return _find_extreme(words, operator.ge)  # ge 对应 >=

def find_longest(words):
    return _find_extreme(words, operator.le)  # le 对应 <=

方法2：直接用Python内置的min/max函数（更简洁） #

Python内置的min和max支持key参数，能直接根据字符串长度筛选结果，一行代码就能实现需求，完全不用自己写循环：

def find_shortest(words):
    return min(words, key=lambda x: len(x)) if words else None

def find_longest(words):
    return max(words, key=lambda x: len(x)) if words else None

内容的提问来源于stack exchange，提问作者anf