py-day2-6 python format字符串格式化

# format() 方法  {}代替元素   默认是从左往右开始取值
test = 'i am {},age {},{}'.format('xiaoma',18,'happy')
print(test)

i am xiaoma,age 18,happy

test1 = 'i am {1},age {0},{2}'.format('','xiaoma','happy')
print(test1)

i am xiaoma,age 18,happy

test2 = 'i am {0},age {0},{0}'.format('','xiaoma','happy')
print(test2)

i am 18,age 18,18

# 字典取值   .format(*[]) 取列表   .format(**{}) 取字典
test3 = 'i am {name},age {age},{city}'.format(name ='xiaoma',age=18,city='china')
print(test3)
test3_1 = 'i am {name},age {age},{city}'.format(**{'name':'xiaoma','age':18,'city':'shanhai'})
print(test3_1)

i am xiaoma,age 18,china
i am xiaoma,age 18,shanhai

# 用{：}取指定类型值
test4 = 'i am {:s},age {:d},{:f}'.format('xiaoma',18,3.1415)
print(test4)

i am xiaoma,age 18,3.141500

# 进制转换 二进制，八进制，十进制···
t = 'number: {:b},{:o},{:d},{:x},{:X},{:%}'.format(15,15,15,15,15,3.1415926)
print(t)

number: 1111,17,15,f,F,314.159260%