%d用做int()方法处理对象
%r用rper()方法处理对象
%s用str()方法处理对象
有些情况下,两者处理的结果是一样的,比如说处理int型对象。
例一:
1
2
3
|
print
"I am %d years old."
%
22
print
"I am %s years old."
%
22
print
"I am %r years old."
%
22
|
返回结果:
1
2
3
|
I am
22
years old.
I am
22
years old.
I am
22
years old.
|
另外一些情况两者就不同了
例二:
1
2
3
|
text
=
"I am %d years old."
%
22
print
"I said: %s."
%
text
print
"I said: %r."
%
text
|
返回结果:
1
2
|
I said: I am
22
years old..
I said:
'I am 22 years old.'
.
/
/
%
r 给字符串加了单引号
|
再看一种情况
例三:
1
2
3
4
|
import
datetime
d
=
datetime.date.today()
print
"%s"
%
d
print
"%r"
%
d
|
返回结果:
1
2
|
2014
-
04
-
14
datetime.date(
2014
,
4
,
14
)
|
可见,%r打印时能够重现它所代表的对象(rper() unambiguously recreate the object it represents)