python 格式化字符串的三种方法

1）%格式化方法

>>> a = "this is %s %s" % ("my", "apple")
>>> a
'this is my apple'

2）内置方法format():

>>> a = "this is {} {}".format("apple","my")
>>> a
'this is apple my'
>>> a = "this is {1} {0}".format("apple","my")   //添加标识，可以控制顺序
>>> a
'this is my apple'
>>> a = "this is {whose} {fruit}".format(fruit = "apple", whose = "my")  //添加有意义的标识，使代码更加友好
>>> a
'this is my apple'

3）使用字典的方式：

>>> a = "this is %(whose)s %(fruit)s" % {"whose":"my", "fruit":"apple"}  //注意：字典用的是{}
>>> a
'this is my apple'