python-格式化字符串

1.如何输出浮点型数据：　　只需输入的是浮点型即可

1 >>> print 5-3
2 2
3 >>> print 5.0-3.0
4 2.0

2.space_in_a_car中的“_”在代码中被假象为空格，用来隔开单词。在变量的命名中，最好能够通过变量的名字一目了然变量的意义，也样方便日后看代码或是别人看代码理解代码。

3.如果使用了非ASCII码编码（如注释中有汉字），需要在文件的第一行加一行代码，如下：　

#--coding:utf-8--#

4.格式化字符串：

　

　输出结果为：

I have 100 cars
My name is lily
I have 100 cars
My naem is lily.
My name is lily, I have 100 car,I am so mZappy

%r,%s的区别：

%r 意思是“不管什么都打印出来”

%s 只打印字符串

1 >>> print "this is a %s"%'apple'
2 this is a apple
3 >>> print "this is a %r"%'apple'
4 this is a 'apple'
5 >>> print "this is a %r"%'[apple]'
6 this is a '[apple]'
7 >>> print "this is a %r"%'%apple%'
8 this is a '%apple%'
9 >>> print "this is a %r"%('%apple%')
10 this is a '%apple%'
11 >>> print "this is a %r"%('(%apple%)')
12 this is a '(%apple%)'

1 >>> x = "this have %d people"%2
2 >>> print "I said: %r"%x
3 I said: 'this have 2 people'
4 >>> print "I said: %r"%("this have %d people"%2)
5 I said: 'this have 2 people'
6 >>> print "I said: %r"%"this have %d people"%2
7 I said: 'this have 2 people'

在输出的格式化字符中含有相乘，需要加括号“（）”，否则会出错

>>> my_height = 74.0
>>> one_in = 2.54
>>> print"%d"%(my_height*one_in)
187
>>> print"%d"%my_height*one_in
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: can't multiply sequence by non-int of type 'float'

格式化字符串符号的总结：http://blog.csdn.net/sding/article/details/4712651