一例生成器sample

举例

def underscore_to_camelcase(s):
    def camelcase():
        yield str.lower
        while True:
            yield str.capitalize

    return ''.join(f(sub) for sub, f in zip(s.split('_'), camelcase()))

拆解

from collections.abc import Iterator


def underscore_to_camelcase(s):
    def camelcase():  # 生成器函数
        yield str.lower
        while True:
            yield str.capitalize

    generator_functions_call_result = camelcase()
    print(type(generator_functions_call_result))  # <class 'generator'>

    zipped = zip(s.split('_'), generator_functions_call_result)
    print(isinstance(zipped, Iterator))  # True, 返回的是迭代器对象, 下面f in zipped是最好的证明

    result = (f(sub) for sub, f in zipped)  # 生成器表达式, f为高阶函数
    print(type(result))  # <class 'generator'>

    return ''.join(result)


print(underscore_to_camelcase("where_are_you"))

1. camelcase是生成器函数，返回str.lower, str.capitalize, str.capitalize ...
2. camelcase()是返回了一个生成器(是迭代器的一种特殊类型)
3. zip() 函数用于将可迭代的对象作为参数，将对象中对应的元素打包成一个个元组，然后返回由这些元组组成的(迭代器)对象, 是惰性的(python2中返回的是List对象)
4. 列表推导式 vs 生成器表达式: 前者是[]后者是()

这样拆分以后就没有那么magic了.