python - !r 叫什么？

Question

我第一次看到这个。我想知道是什么!r在调用的代码的最后一行中，以便我可以搜索它。我在以下位置找到了这段代码:https://adamj.eu/tech/2020/08/10/a-guide-to-python-lambda-functions/

class Puppy:
    def __init__(self, name, cuteness):
        self.name = name
        self.cuteness = cuteness

    def __repr__(self):
        return f"Puppy({self.name!r}, {self.cuteness!r})"

Answer 1

这是一个格式字符串 conversion flag告诉格式化程序调用 repr在格式化字符串之前在对象上。

Three conversion flags are currently supported: '!s' which calls str() on the value, '!r' which calls repr() and '!a' which calls ascii().