使用f-string格式化字符串十分简单。唯一的要求就是给它一个有效的表达式。f-string 也可以用大写F开头或者与 r 原始字符串结合使用。但是不能将其与 b” “ 或者 u” “ 混用。

>>> book = "The dog guide"
>>> num_pages = 124
>>> f"The book {book} has{num_pages} pages"
'The book The dog guide has 124 pages'
>>> F"The book {book} has{num_pages} pages"
'The book The dog guide has 124 pages'
>>> print(Fr"The book {book} has{num_pages} pages\n")
The book The dog guide has 124 pages\n 
>>> print(FR"The book {book} has{num_pages} pages\n")
The book The dog guide has 124 pages\n
>>> print(f"The book {book} has{num_pages} pages\n")
The book The dog guide has 124 pages