python--003--百分号字符串拼接、format

 

1. %s后可根字符或数字，%d只能是数字, %f代表浮点数

msg='i am %s, my hobby is%s'%('wendy','alex')
print(msg)
msg='i am %s,my hobby is%s'%('wendy',1)
msg='i am %s,my hobby is %s'%('wendy',[1,2])
print(msg)
msg='i am %s,myhobby is %d'%('wendy',1)

#%f代表浮点数

tp1="present%f" %99.97247844
tp1="present%.2f" %99.97247844
print(tp1)

output:
     i am lhf, my hobby isalex
     i am lhf,my hobby is [1, 2]
     present99.97

 

#取4个字符
tp1="present %.4s"%'abcdefgs'
print(tp1)

#打印百分号
tp1="present %s%%"%99.97247844
print(tp1)

tp1='i am %(name)s age %(age)d'%{"name":"wendy","age":8}
print(tp1)

output:
    present abcd
    present 99.97247844%
    i am wendy age 8

 

2. 字符串格式化有两种方式：百分号方式、format方式

# -左对齐+右对齐
tp1='i am %(name)-20s age %(age)d'%{"name":"wendy","age":8}
print(tp1)

#加颜色:46表示颜色的色号可调整，固定开头：33[46;1m结尾：33[0m，他们中间的位置加颜色
msg='i am 33[46;1m%(name)+20s33[0m my hobby is running'%{"name":"senven"}
print(msg)

output:
    i am wendy                age 8
    i am               senven my hobby is running      注：senven有背景颜色

 

3. format

#必须要一一对应
tp1="i am {},age {},{}".format("seven",19,"alex")
print(tp1)

#利用{0}{1}{2}这种，可以不用一一对应，可以不按顺序
tp1="i am {2},age {1},{0}".format("seven",19,"alex")
print(tp1)
tp1="i am {1},age {1}".format("seven",19,"alex")
print(tp1)

tp1="i am {name},age {age},really {name}".format(name="seven",age=19)
print(tp1)

tp1="i am {name},age {age},really{name}".format(**{"name":"seven","age":19})
print(tp1)

output：
    i am seven,age 19,alex
    i am alex,age 19,seven
    i am 19,age 19
    i am seven,age 19,really seven
    i am seven,age 19,reallyseven

　　

# format最后相当于将后面的传值转为元组
tp1 = "i am {0[0]},age {0[1]},{0[2]}".format([1, 2, 3], [11, 22, 33])
print(tp1)

# *表示传列表，**表示传字典
tp1 = "i am {:s},age {:d},money {:f}".format(*["seven", 18, 8888.1])
print(tp1)

output：
    i am 1,age 2,3
    i am seven,age 18,money 8888.100000