什么是 print(f"...")

我正在阅读一个 python 脚本，该脚本接受 XML 文件的输入并输出 XML 文件。但是，我不明白打印语法。有人可以解释一下吗f in print(f"...") does?

args = parser.parser_args()

print(f"Input directory: {args.input_directory}")
print(f"Output directory: {args.output_directory}")

The f means 格式化字符串文字 https://docs.python.org/3.6/reference/lexical_analysis.html#formatted-string-literals这是新的Python 3.6.

A 格式化字符串文字 or f-string是一个字符串文字 前缀为f or F。这些字符串可能包含替换 字段，是由大括号分隔的表达式{}。尽管 其他字符串文字始终具有常量值、格式化字符串 实际上是在运行时评估的表达式。

格式化字符串文字的一些示例：

>>> name = "Fred"
>>> f"He said his name is {name}."
"He said his name is Fred."

>>> name = "Fred"
>>> f"He said his name is {name!r}."
"He said his name is Fred."

>>> f"He said his name is {repr(name)}." # repr() is equivalent to !r
"He said his name is Fred."

>>> width = 10
>>> precision = 4
>>> value = decimal.Decimal("12.34567")
>>> f"result: {value:{width}.{precision}}" # nested fields
result: 12.35

>>> today = datetime(year=2023, month=1, day=27)
>>> f"{today:%B %d, %Y}" # using date format specifier
January 27, 2023

>>> number = 1024
>>> f"{number:#0x}" # using integer format specifier
0x400