python3.6使用f-string来格式化字符串，,这里的f-strin

python3.6使用f-string来格式化字符串，,这里的f-strin

这里的f-string指的是以f或F修饰的字符串，在字符串中使用{}来替换变量，表达式和支持各种格式的输出。详细的格式化定义可以看官方文档

>>> a, b = 30, 20>>> print(f"the result of 30 - 20 is {a - b}")the result of 30 - 20 is 10>>> import datetime>>> print(f"now is {datetime.datetime.today()}")now is 2019-03-14 00:49:44.853937>>> 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=2017, month=1, day=27)>>> f"{today:%B %d, %Y}"  # using date format specifier'January 27, 2017'>>> number = 1024>>> f"{number:#0x}"  # using integer format specifier'0x400'

python3.6使用f-string来格式化字符串