python中的格式化输出用法总结

> '%s %d-%d' % ('hello', 7, 1)
'hello 7-1'

> '{0} {1}:{2}'.format('hello', '1', '7')
'hello 1:7'

> '%.3f' % 1.234567869
'1.235'

> for i in range(5):
... '%.*f' % (i, 1.234234234234234)
...
'1'
'1.2'
'1.23'
'1.234'
'1.2342'

> for i in range(5):
...  '{0:.{1}f}'.format(1 / 3.0, i)
...
'0'
'0.3'
'0.33'
'0.333'
'0.3333'

> replay = """
... Hello World Cup...
... Germany vs Brazil
... %(germany)d : %(brazil)d"""
> print(replay % {'germany': 7, 'brazil': 1})
Hello World Cup...
Germany vs Brazil
7 : 1

> germany = 7
> brazil = 1
> '%(germany)d : %(brazil)d' % vars()
'7 : 1'

> 'My {1[kind]} runs {0.platform}'.format(sys, {'kind': 'pc'})
'My pc runs linux'
> 'My {map[kind]} runs {sys.platform}'.format(sys=sys, map={'kind': 'pc'})
'My pc runs linux'

> somelist = list('SPAM')
> 'first={0[0]}, third={0[2]}'.format(somelist)
'first=S, third=A'
> 'first={0}, last={1}'.format(somelist[1], somelist[-1])
'first=P, last=M'
> parts = somelist[0], somelist[-1], somelist[1:-1]
> 'first={0}, last={1}, middle={2}'.format(*parts)
"first=S, last=M, middle=['P', 'A']"
>