字符串格式化

百分号方式

1.（1）  %s  传递字符串、列表等等  (%.ns  截取传入字符串的前n位传入）

dmsg = ' i am %s ,my hobby is %s' %('jiao','basketball')
print(msg)
运行结果： i am jiao ,my hobby is basketball

（2）%d 传递数字，其他数据类型不行

2.打印浮点数  %.(n)f    通过设置n来确定保留几位，

tpl = 'percent %.5f' % 1.66564848123135
print(tpl)
运行结果：percent 1.66565

3.打印百分比  %%

tpl =  '%.5f %%' %1.66564848123135
print(tpl)
运行结果：1.66565 %

4.用键值对进行拼接

msg = 'i am %(name)s ,i am %(age)d years old' % {'name':'jiao ','age':18 }
print(msg)
运行结果：i am jiao  ,i am 18 years old

5.拼接

print('j','i','a','o',sep='_')
运行结果：j_i_a_o

format方式

1.传值，

　　（1）必须是一一对应，否则将会报错

msg = 'i am {} ,my age is {}'.format('jiao',18)
print(msg)
运行结果：i am jiao ,my age is 18

 　　（2）可以通过在大括号中添加序号的方式

msg = 'i am {1} ,my age is {0},my hobby is {2}'.format('jiao',18,'basketball')
print(msg)
运行结果：i am 18 ,my age is jiao,my hobby is basketball

还可以：tpl = ' i am {0[0]},age{0[0]},really {1[2]}'.format([1,2,3],[11,22,33])

　　  (3)设置名称进行传值 ，format口括号内顺序无要求

msg = 'i am {name} ,my age is {age},my hobby is {hobby}'.format(age=18,name='jiao',hobby='basketball')
print(msg)
运行结果：i am jiao ,my age is 18,my hobby is basketball