python中字符串的格式化

python中字符串的格式化。

1、format

位置参数

>>> "{0} and {1}".format("aaa","bbb")
'aaa and bbb'
>>> "{0},{1} and {2}".format("aaa","bbb","ccc")
'aaa,bbb and ccc'

 

关键字参数

>>> "{a},{b} and {c}".format(c = "xxx",a = "mmm",b = "qqq")
'mmm,qqq and xxx'

 

>>> "{0}:{1:.2f}".format("圆周率：",3.1415926)
'圆周率：:3.14'

 

2、格式化操作符 %

格式化字符串：%s

>>> "%s" % "abcd"
'abcd'

 

格式化整数：%d

>>> "%d" % 100
'100'
>>> "%d" % 100.434
'100'

 

格式化浮点数：%f

>>> "%f" % 100.34245
'100.342450'
>>> "%f" % 100
'100.000000'

 

科学计数法：%e

>>> "%e" % 1000
'1.000000e+03'