如何将Python中的f-strings转换为format()方法？

首先要纠正你代码里的一个逻辑错误：原条件if 'fruit' and 'juice' in kwargs:写法有误，它实际只会判断'juice' in kwargs（非空字符串'fruit'本身会被视为True），正确写法应该是if 'fruit' in kwargs and 'juice' in kwargs:，这样才能确保两个参数都存在于kwargs中。

下面提供两种将f-strings替换为format()方法的实现方式：

1. 位置参数形式 #

按顺序传入需要填充的值，适合参数较少的场景：

def myfunc(*args, **kwargs):
    if 'fruit' in kwargs and 'juice' in kwargs:
        print("I like {} and my favorite fruit is {}".format(' and '.join(args), kwargs['fruit']))
        print("May I have some {} juice?".format(kwargs['juice']))
    else:
        pass
        
myfunc('eggs','spam',fruit='cherries',juice='orange')

2. 命名参数形式 #

使用命名占位符，代码可读性更强，尤其参数较多时更清晰：

def myfunc(*args, **kwargs):
    if 'fruit' in kwargs and 'juice' in kwargs:
        print("I like {items} and my favorite fruit is {fruit}".format(
            items=' and '.join(args),
            fruit=kwargs['fruit']
        ))
        print("May I have some {juice} juice?".format(juice=kwargs['juice']))
    else:
        pass
        
myfunc('eggs','spam',fruit='cherries',juice='orange')

两种写法运行结果与原代码完全一致，输出内容为：

I like eggs and spam and my favorite fruit is cherries
May I have some orange juice?

内容的提问来源于stack exchange，提问作者Ngọc Yến