python - 如何在隐式字符串连接中处理 f 字符串？

Question

我犯了这个错误:

key, value = 'K', 999
msg = (
    f"key={key}, "
    "value={value}"  # needs to be prefixed with f as well
    )
# key=K, value={value}

并开始想知道 Python 如何处理复杂的文字连接情况。

假设一个字符串是 f-string(格式化字符串文字)，另一个字符串是普通字符串文字，如上例所示。 Python 会在编译时连接这两个字符串吗？如果是，结果是什么？

Answer 1

来自PEP 498 :

Adjacent f-strings and regular strings are concatenated. Regular strings are concatenated at compile time, and f-strings are concatenated at run time.

Each f-string is entirely evaluated before being concatenated to adjacent f-strings.