python全栈开发笔记---------字符串格式化

msg =‘i am %s my body‘ %‘ales‘
print(msg)  #i am ales my body

msg =‘i am %s my body is %s‘ %(‘alex‘,‘xiaoming‘) #穿多个值加括号
print(msg) #i am alex my body is xiaoming

tpl = "percent %f" %99.978979934
print(tpl)  #percent 99.978980   默认保留小数点后6位

tpl = "percent %.2f" %99.978979934
print(tpl)  #percent 99.98  加.2后 是取小数点后2位，取整四舍五入

tpl = "percent %.2f  %%" %99.978979934
print(tpl)  #percent 99.98  % 打印百分号

tpl = ‘i am %(name)s age %(age)d‘ %{"name":"alex","age":19}
print(tpl)  #i am alex age 19   用键值的形式来传值（字典）

print(‘root‘,‘x‘,‘0‘,‘1‘ ,sep=‘:‘)  #root:x:0:1  字符串拼接 实现比用‘+’连接起来更简单，而且不容易弄错。