Python中用format函数格式化字符串的用法

In [1]: '{0},{1}'.format('kzc',18) 
Out[1]: 'kzc,18' 
In [2]: '{},{}'.format('kzc',18) 
Out[2]: 'kzc,18' 
In [3]: '{1},{0},{1}'.format('kzc',18) 
Out[3]: '18,kzc,18'

In [5]: '{name},{age}'.format(age=18,name='kzc') 
Out[5]: 'kzc,18'

class Person: 
  def __init__(self,name,age): 
    self.name,self.age = name,age 
    def __str__(self): 
      return 'This guy is {self.name},is {self.age} old'.format(self=self) 

In [2]: str(Person('kzc',18)) 
Out[2]: 'This guy is kzc,is 18 old'

In [7]: p=['kzc',18]
In [8]: '{0[0]},{0[1]}'.format(p)
Out[8]: 'kzc,18'

In [15]: '{:>8}'.format('189')
Out[15]: '   189'
In [16]: '{:0>8}'.format('189')
Out[16]: '00000189'
In [17]: '{:a>8}'.format('189')
Out[17]: 'aaaaa189'

In [44]: '{:.2f}'.format(321.33345)
Out[44]: '321.33'

In [54]: '{:b}'.format(17)
Out[54]: '10001'
In [55]: '{:d}'.format(17)
Out[55]: '17'
In [56]: '{:o}'.format(17)
Out[56]: '21'
In [57]: '{:x}'.format(17)
Out[57]: '11'

In [47]: '{:,}'.format(1234567890)
Out[47]: '1,234,567,890'