Python学习日志（不断更新）

前两天安装好了Fedora12，接下来开始在Linux上来学习Python。参考书籍《Python基础教程（第2版）》

python中除法默认是整除，如1／2等于0，如果要改变这种特性，方法如下：
方法一：
[hxc@localhost ~]$ python -Qnew
方法二：进入python后执行from __future__ import division（注：future前后都是两个下划线）

在命令行直接运行python程序
在程序文件中加入#!/usr/bin/env python。例如：
[hxc@localhost ~]$ vi hello.py （内容如下：）
#!/usr/bin/env python
name = raw_input("What is your name?")
print "Hello, "+name+"!"

（保存退出）
[hxc@localhost ~]$ chmod a+x hello.py
[hxc@localhost ~]$ ./hello.py

字符串：
>>> "Hello, World!"
'Hello, World!'
>>>
>>> 'Hello, World!'
'Hello, World!'
>>> "Let's go!"
"Let's go!"
>>> 'Let's go!'
  File "<stdin>", line 1
    'Let's go!'
         ^
SyntaxError: invalid syntax
>>> 'Let\'s go!'
"Let's go!"
>>>
str函数、repr函数与反引号（不是单引号）
>>> temp=42
>>> print "The temperature is "+temp
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: cannot concatenate 'str' and 'int' objects
>>> print "The temperature is "+str(temp)
The temperature is 42
>>> print "The temperature is "+temp
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: cannot concatenate 'str' and 'int' objects
>>> print "The temperature is "+'temp'
The temperature is temp
>>> print "The temperature is "+`temp`
The temperature is 42
>>> print repr(100000L)
100000L
>>> print str(100000L)
100000
>>> print str("Hello, world!")
Hello, world!
>>> print repr("Hello, world!")
'Hello, world!'

原始字符串
>>> path="C:\there"
>>> print path
C:    here
>>> path=r"C:\there"
>>> print path
C:\there
>>> path=r"C:\there\"
  File "<stdin>", line 1
    path=r"C:\there\"
                    ^
SyntaxError: EOL while scanning string literal
>>> path=r"C:\there\\"
>>> path=r"C:\there\\"
>>> path=r"C:\there" "\\"
>>> print path
C:\there\
>>>