python占位符介绍及操作方法

1，常用占用符：　

常见的占位符有：
%d    整数
%f    浮点数
%s    字符串
%x    十六进制整数
使用方法：
tpl = "i am %s" % "alex"

 

 tpl = "i am %s age %d" % ("alex", 18)

 

 tpl = "i am %(name)s age %(age)d" % {"name": "alex", "age": 18}

 

 tpl = "percent %.2f" % 99.97623

 

 tpl = "i am %(pp).2f" % {"pp": 123.425556, }

 

 tpl = "i am %.2f %%" % {"pp": 123.425556, }

 

2，Format方法：

tpl = "i am {}, age {}, {}".format("seven", 18, 'alex')

  

tpl = "i am {}, age {}, {}".format(*["seven", 18, 'alex'])

  

tpl = "i am {0}, age {1}, really {0}".format("seven", 18)

  

tpl = "i am {0}, age {1}, really {0}".format(*["seven", 18])

  

tpl = "i am {name}, age {age}, really {name}".format(name="seven", age=18)

  

tpl = "i am {name}, age {age}, really {name}".format(**{"name": "seven", "age": 18})

  

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

  

tpl = "i am {:s}, age {:d}, money {:f}".format("seven", 18, 88888.1)

  

tpl = "i am {:s}, age {:d}".format(*["seven", 18])

  

tpl = "i am {name:s}, age {age:d}".format(name="seven", age=18)

  

tpl = "i am {name:s}, age {age:d}".format(**{"name": "seven", "age": 18})

 

tpl = "numbers: {:b},{:o},{:d},{:x},{:X}, {:%}".format(15, 15, 15, 15, 15, 15.87623, 2)

 

tpl = "numbers: {:b},{:o},{:d},{:x},{:X}, {:%}".format(15, 15, 15, 15, 15, 15.87623, 2)

 

tpl = "numbers: {0:b},{0:o},{0:d},{0:x},{0:X}, {0:%}".format(15)

 

tpl = "numbers: {num:b},{num:o},{num:d},{num:x},{num:X}, {num:%}".format(num=15)