1、打印字符串print("My name is %s" %("Alfred.Xue"))#输出效果：My name is Alfred.Xue
2、打印整数print("I am %d years old." %(25))#输出效果：I am 25 years old.
3、打印浮点数print ("His height is %f m"%(1.70))#输出效果：His height is 1.700000 m
4、指定占位符宽度print ("Name:%10s Age:%8d Height:%8.2f"%("Alfred",25,1.70))#输出效果：Name: Alfred Age: 25 Height: 1.70
5、指定占位符宽度（左对齐）print ("Name:%-10s Age:%-8d Height:%-8.2f"%("Alfred",25,1.70))#输出效果：Name:Alfred Age:25 Height:1.70
6、指定占位符（只能用0当占位符？）print ("Name:%-10s Age:%08d Height:%08.2f"%("Alfred",25,1.70))#输出效果：Name:Alfred Age:00000025 Height:00001.70
7、科学计数法format(0.0026,'.2e')#输出效果：'2.60e-03'
8、字符串格式化代码：
