Python格式化之format()格式化

利用format()方法实现字符串格式化

%占位符的方式要刻意区分变量类型，format()方法则无需考虑变量类型

>>> a = 'teacher'
>>> b = 92.3675
>>> print('hello {0}, your score is {1}, good luck for {0}'.format(a,b))
hello teacher, your score is 92.3675, good luck for teacher
>>> 

在{}中也可不指定序号，只要在format()中按顺序指定变量即可

>>> a = 'teacher'
>>> b = 92.3675
>>> print('hello {}, your score is {}, good luck for {}'.format(a,b,a))
hello teacher, your score is 92.3675, good luck for teacher
>>> 

利用format()方法指定小数位数

>>> a = 'teacher'
>>> b = 92.3675
>>> print('hello {}, your score is {:.1f}, good luck for {}'.format(a,b,a))
hello teacher, your score is 92.4, good luck for teacher
>>> 

格式化百分数

>>> 'You score is {0:.1%}'.format(0.8976)   #不指定序号，'You score is {:.1%}'.format(0.8976)
'You score is 89.8%'
>>> 

实现等宽输出

>>> year = 2020
>>> month = 1
>>> day = 4
>>> '{0}-{1:02d}-{2:02d}'.format(year,month,day)  #不指定序号，'{}-{:02d}-{:02d}'.format(year,month,day)
'2020-01-04'
>>>