1.format后面都是个元组类型！！！
不一一对应则报错，比如少了一个替换的元素
括号里可以加索引，看例2
可以用索引只取一个值，比如括号里都是｛1｝
r = "i am {}, i am {} yearsold".format("nana",18) print(r) i am nana, i am 18 yearsold
r = "i am {1}, i am {0} yearsold".format("nana",18) print(r) i am 18, i am nana yearsold
2.注意后面用小括号，根据format语法运用符号
也可以用字典的形式，但是注意加*号以及中括号，比如例2
r = "i am {name}, i am {age} yearsold".format(name = "nana",age = 18) print(r) i am nana, i am 18 yearsold
r = "i am {name}, i am {age} yearsold".format(**{"name": "nana","age":18}) print(r) i am nana, i am 18 yearsold
3.
原文：https://www.cnblogs.com/newt/p/8987883.html