看到如下代码，不明白这里*的用法，似乎是将size分解为类定义中的两个属性的意思：
size = self.GetClientSize()
glViewport( 0,0, *size)            #相当于glViewport( 0,0, size.width,
size.height)
请教大家*号这种用法的意思和该用在什么地方，谢谢。
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size 是一个tuple
http://groups.google.com/group/python-cn/browse_thread/thread/171562599ef2f9f1/518a3f0f021e9263?lnk=gst&q;=%E4%BC%A0%E9%80%81%E5%85%83%E7%BB%84%E7%9A%84*%E8%BF%98%E5%8F%AF%E4%BB%A5%E6%94%BE%E5%85%A5%E5%87%BD%E6%95%B0%3F++&rnum;=1#518a3f0f021e9263

On 10/23/06, jiang hongbo <larkdream at gmail.com> wrote:
>
> 看到如下代码，不明白这里*的用法，似乎是将size分解为类定义中的两个属性的意思：
> size = self.GetClientSize()
> glViewport( 0,0, *size)            #相当于glViewport( 0,0, size.width,
> size.height)
> 请教大家*号这种用法的意思和该用在什么地方，谢谢。
>
> _______________________________________________
> python-chinese
> Post: send python-chinese at lists.python.cn
> Subscribe: send subscribe to python-chinese-request at lists.python.cn
> Unsubscribe: send unsubscribe to  python-chinese-request at lists.python.cn
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>



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代表这个参数是一个列表或者是元组。
2个星号代表是一个字典。

在 06-10-23，jiang hongbo<larkdream在gmail.com> 写道：
> 看到如下代码，不明白这里*的用法，似乎是将size分解为类定义中的两个属性的意思：
> size = self.GetClientSize()
> glViewport( 0,0, *size)            #相当于glViewport( 0,0, size.width,
> size.height)
> 请教大家*号这种用法的意思和该用在什么地方，谢谢。
> _______________________________________________
> python-chinese
> Post: send python-chinese在lists.python.cn
> Subscribe: send subscribe to
> python-chinese-request在lists.python.cn
> Unsubscribe: send unsubscribe to
> python-chinese-request在lists.python.cn
> Detail Info:
> http://python.cn/mailman/listinfo/python-chinese
>

举个例子，下面的函数fun×完成显示参数的功能：
def fun1(arg1,arg2,arg3):
    print arg1,arg2,arg3,
fun1(1,2,3)

def fun2(args):
    for i in args:print i,
fun2([1,2,3])
fun2([1,2,3,4])

def fun3(*args)
    for i in args:print i,
fun3(1,2,3,4,5)
fun3(1,2)
比较三个函数可以看出
fun2比fun1灵活，因为fun1的参数个数固定
fun3比fun2灵活，因为fun3的多个参数都不必用序列来传递，这在实现参数个数不
定的函数时很有用；

至于**类似,只是**表示的是带关键字的参数
def fun4(**args):
    for k,v in enumerate(args):
       print k,v
fun4(id=1001,name='xx')
fun4(id=1001,name='xx',age=28)

马踏飞燕 写道:
> 代表这个参数是一个列表或者是元组。
> 2个星号代表是一个字典。
>
> 在 06-10-23，jiang hongbo<larkdream at gmail.com> 写道：
>   
>> 看到如下代码，不明白这里*的用法，似乎是将size分解为类定义中的两个属性的意思：
>> size = self.GetClientSize()
>> glViewport( 0,0, *size)            #相当于glViewport( 0,0, size.width,
>> size.height)
>> 请教大家*号这种用法的意思和该用在什么地方，谢谢。
>> _______________________________________________
>> python-chinese
>> Post: send python-chinese at lists.python.cn
>> Subscribe: send subscribe to
>> python-chinese-request at lists.python.cn
>> Unsubscribe: send unsubscribe to
>> python-chinese-request at lists.python.cn
>> Detail Info:
>> http://python.cn/mailman/listinfo/python-chinese
>>
>>     
> _______________________________________________
> python-chinese
> Post: send python-chinese at lists.python.cn
> Subscribe: send subscribe to python-chinese-request at lists.python.cn
> Unsubscribe: send unsubscribe to  python-chinese-request at lists.python.cn
> Detail Info: http://python.cn/mailman/listinfo/python-chinese

Õý½â£¡


Qutr£¬qutianrang在gmail.com
2006-10-23 
----- Original Message ----- 
From: amingsc 
To: python-chinese 
Sent: 2006-10-23, 09:58:12
Subject: Re: [python-chinese] Çë½Ì *µÄÒâ˼


¾Ù¸öÀý×Ó£¬ÏÂÃæµÄº¯Êýfun¡ÁÍê³ÉÏÔʾ²ÎÊýµÄ¹¦ÄÜ£º
def fun1(arg1,arg2,arg3):
    print arg1,arg2,arg3,
fun1(1,2,3)

def fun2(args):
    for i in args:print i,
fun2([1,2,3])
fun2([1,2,3,4])

def fun3(*args)
    for i in args:print i,
fun3(1,2,3,4,5)
fun3(1,2)
±È½ÏÈý¸öº¯Êý¿ÉÒÔ¿´³ö
fun2±Èfun1Áé»î£¬ÒòΪfun1µÄ²ÎÊý¸öÊý¹Ì¶¨
fun3±Èfun2Áé»î£¬ÒòΪfun3µÄ¶à¸ö²ÎÊý¶¼²»±ØÓÃÐòÁÐÀ´´«µÝ£¬ÕâÔÚʵÏÖ²ÎÊý¸öÊý²»
¶¨µÄº¯ÊýʱºÜÓÐÓã»

ÖÁÓÚ**ÀàËÆ,Ö»ÊÇ**±íʾµÄÊÇ´ø¹Ø¼ü×ֵIJÎÊý
def fun4(**args):
    for k,v in enumerate(args):
       print k,v
fun4(id=1001,name='xx')
fun4(id=1001,name='xx',age=28)

Âí̤·ÉÑà дµÀ:
> ´ú±íÕâ¸ö²ÎÊýÊÇÒ»¸öÁбí»òÕßÊÇÔª×é¡£
> 2¸öÐǺŴú±íÊÇÒ»¸ö×ֵ䡣
>
> ÔÚ 06-10-23£¬jiang hongbo<larkdream在gmail.com> дµÀ£º
> 
>> ¿´µ½ÈçÏ´úÂ룬²»Ã÷°×ÕâÀï*µÄÓ÷¨£¬ËƺõÊǽ«size·Ö½âΪÀඨÒåÖеÄÁ½¸öÊôÐÔµÄÒâ˼£º
>> size = self.GetClientSize()
>> glViewport( 0,0, *size) #Ï൱ÓÚglViewport( 0,0, size.width,
>> size.height)
>> Çë½Ì´ó¼Ò*ºÅÕâÖÖÓ÷¨µÄÒâ˼ºÍ¸ÃÓÃÔÚʲôµØ·½£¬Ð»Ð»¡£
>> _______________________________________________
>> python-chinese
>> Post: send python-chinese在lists.python.cn
>> Subscribe: send subscribe to
>> python-chinese-request在lists.python.cn
>> Unsubscribe: send unsubscribe to
>> python-chinese-request在lists.python.cn
>> Detail Info:
>> http://python.cn/mailman/listinfo/python-chinese
>>
>> 
> _______________________________________________
> python-chinese
> Post: send python-chinese在lists.python.cn
> Subscribe: send subscribe to python-chinese-request在lists.python.cn
> Unsubscribe: send unsubscribe to python-chinese-request在lists.python.cn
> Detail Info: http://python.cn/mailman/listinfo/python-chinese

_______________________________________________
python-chinese
Post: send python-chinese在lists.python.cn
Subscribe: send subscribe to python-chinese-request在lists.python.cn
Unsubscribe: send unsubscribe to python-chinese-request在lists.python.cn
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你所讲解的,是在形参(parameters)中，这种用法是python比较基本的。
但是楼主说的情况，似乎是*用在了实参(arguments)中，似乎是把一个列表替换成其 
各个成员填入形参中。这种用法，我还是第一次看到~

查了一下Python Reference Manual， 在5.3.4 Calls中，看到了这种用法：

If the syntax "*expression" appears in the function call, "expression"  
must evaluate to a sequence. Elements from this sequence are treated as if  
they were additional positional arguments; if there are postional  
arguments x1,...,xN , and "expression" evaluates to a sequence y1,...,yM,  
this is equivalent to a call with M+N positional arguments  
x1,...,xN,y1,...,yM.

If the syntax "**expression" appears in the function call, "expression"  
must evaluate to a (subclass of) dictionary, the contents of which are  
treated as additional keyword arguments. In the case of a keyword  
appearing in both "expression" and as an explicit keyword argument, a  
TypeError exception is raised.


对于在函数调用中，传入实参有形为*exp的，则exp必须是一个序列类型，将exp序列 
中的每一个元素按顺序填入到该函数的形参列表中：
>>> def fun(a, b, c, d):
...     print a, b, c, d
...
>>> li = [7,8]
>>> fun(1,2, *li)
1 2 7 8
>>>

对于在函数调用中，传入实参有形为**exp的，则exp必须是一个字典，将exp字典的内 
容，以关键字参数的方式填入函数的形参中，例子还是上面的fun()函数：
>>> di = {'b':7, 'c':8}
>>> fun(1, d=4, **di)
1 7 8 4
>>>


On Mon, 23 Oct 2006 09:58:12 +0800, amingsc  
<amingsc at gmail.com> wrote:

> 举个例子，下面的函数fun×完成显示参数的功能：
> def fun1(arg1,arg2,arg3):
>     print arg1,arg2,arg3,
> fun1(1,2,3)
>
> def fun2(args):
>     for i in args:print i,
> fun2([1,2,3])
> fun2([1,2,3,4])
>
> def fun3(*args)
>     for i in args:print i,
> fun3(1,2,3,4,5)
> fun3(1,2)
> 比较三个函数可以看出
> fun2比fun1灵活，因为fun1的参数个数固定
> fun3比fun2灵活，因为fun3的多个参数都不必用序列来传递，这在实现参数个数不
> 定的函数时很有用；
>
> 至于**类似,只是**表示的是带关键字的参数
> def fun4(**args):
>     for k,v in enumerate(args):
>        print k,v
> fun4(id=1001,name='xx')
> fun4(id=1001,name='xx',age=28)
>
> 马踏飞燕 写道:
>> 代表这个参数是一个列表或者是元组。
>> 2个星号代表是一个字典。
>>
>> 在 06-10-23，jiang hongbo<larkdream at gmail.com> 写道：
>>
>>> 看到如下代码，不明白这里*的用法，似乎是将size分解为类定义中的两个属性的 
>>> 意思：
>>> size = self.GetClientSize()
>>> glViewport( 0,0, *size)            #相当于glViewport( 0,0, size.width,
>>> size.height)
>>> 请教大家*号这种用法的意思和该用在什么地方，谢谢。
>>> _______________________________________________
>>> python-chinese
>>> Post: send python-chinese at lists.python.cn
>>> Subscribe: send subscribe to
>>> python-chinese-request at lists.python.cn
>>> Unsubscribe: send unsubscribe to
>>> python-chinese-request at lists.python.cn
>>> Detail Info:
>>> http://python.cn/mailman/listinfo/python-chinese
>>>
>>>
>> _______________________________________________
>> python-chinese
>> Post: send python-chinese at lists.python.cn
>> Subscribe: send subscribe to python-chinese-request at lists.python.cn
>> Unsubscribe: send unsubscribe to  python-chinese-request at lists.python.cn
>> Detail Info: http://python.cn/mailman/listinfo/python-chinese
>
> _______________________________________________
> python-chinese
> Post: send python-chinese at lists.python.cn
> Subscribe: send subscribe to python-chinese-request at lists.python.cn
> Unsubscribe: send unsubscribe to  python-chinese-request at lists.python.cn
> Detail Info: http://python.cn/mailman/listinfo/python-chinese



-- 
Using Opera's revolutionary e-mail client: http://www.opera.com/mail/

thank you

On 10/23/06, Leira Hua <lhua在altigen.com.cn> wrote:
>
> 你所讲解的,是在形参(parameters)中，这种用法是python比较基本的。
> 但是楼主说的情况，似乎是*用在了实参(arguments)中，似乎是把一个列表替换成其
> 各个成员填入形参中。这种用法，我还是第一次看到~
>
> 查了一下Python Reference Manual， 在5.3.4 Calls中，看到了这种用法：
>
> If the syntax "*expression" appears in the function call, "expression"
> must evaluate to a sequence. Elements from this sequence are treated as if
> they were additional positional arguments; if there are postional
> arguments x1,...,xN , and "expression" evaluates to a sequence y1,...,yM,
> this is equivalent to a call with M+N positional arguments
> x1,...,xN,y1,...,yM.
>
> If the syntax "**expression" appears in the function call, "expression"
> must evaluate to a (subclass of) dictionary, the contents of which are
> treated as additional keyword arguments. In the case of a keyword
> appearing in both "expression" and as an explicit keyword argument, a
> TypeError exception is raised.
>
>
> 对于在函数调用中，传入实参有形为*exp的，则exp必须是一个序列类型，将exp序列
> 中的每一个元素按顺序填入到该函数的形参列表中：
> >>> def fun(a, b, c, d):
> ...     print a, b, c, d
> ...
> >>> li = [7,8]
> >>> fun(1,2, *li)
> 1 2 7 8
> >>>
>
> 对于在函数调用中，传入实参有形为**exp的，则exp必须是一个字典，将exp字典的内
> 容，以关键字参数的方式填入函数的形参中，例子还是上面的fun()函数：
> >>> di = {'b':7, 'c':8}
> >>> fun(1, d=4, **di)
> 1 7 8 4
> >>>
>
>
> On Mon, 23 Oct 2006 09:58:12 +0800, amingsc
> <amingsc在gmail.com> wrote:
>
> > 举个例子，下面的函数fun×完成显示参数的功能：
> > def fun1(arg1,arg2,arg3):
> >     print arg1,arg2,arg3,
> > fun1(1,2,3)
> >
> > def fun2(args):
> >     for i in args:print i,
> > fun2([1,2,3])
> > fun2([1,2,3,4])
> >
> > def fun3(*args)
> >     for i in args:print i,
> > fun3(1,2,3,4,5)
> > fun3(1,2)
> > 比较三个函数可以看出
> > fun2比fun1灵活，因为fun1的参数个数固定
> > fun3比fun2灵活，因为fun3的多个参数都不必用序列来传递，这在实现参数个数不
> > 定的函数时很有用；
> >
> > 至于**类似,只是**表示的是带关键字的参数
> > def fun4(**args):
> >     for k,v in enumerate(args):
> >        print k,v
> > fun4(id=1001,name='xx')
> > fun4(id=1001,name='xx',age=28)
> >
> > 马踏飞燕 写道:
> >> 代表这个参数是一个列表或者是元组。
> >> 2个星号代表是一个字典。
> >>
> >> 在 06-10-23，jiang hongbo<larkdream在gmail.com> 写道：
> >>
> >>> 看到如下代码，不明白这里*的用法，似乎是将size分解为类定义中的两个属性的
> >>> 意思：
> >>> size = self.GetClientSize()
> >>> glViewport( 0,0, *size)            #相当于glViewport( 0,0, size.width,
> >>> size.height)
> >>> 请教大家*号这种用法的意思和该用在什么地方，谢谢。
> >>> _______________________________________________
> >>> python-chinese
> >>> Post: send python-chinese在lists.python.cn
> >>> Subscribe: send subscribe to
> >>> python-chinese-request在lists.python.cn
> >>> Unsubscribe: send unsubscribe to
> >>> python-chinese-request在lists.python.cn
> >>> Detail Info:
> >>> http://python.cn/mailman/listinfo/python-chinese
> >>>
> >>>
> >> _______________________________________________
> >> python-chinese
> >> Post: send python-chinese在lists.python.cn
> >> Subscribe: send subscribe to python-chinese-request在lists.python.cn
> >> Unsubscribe: send unsubscribe to
> python-chinese-request在lists.python.cn
> >> Detail Info: http://python.cn/mailman/listinfo/python-chinese
> >
> > _______________________________________________
> > python-chinese
> > Post: send python-chinese在lists.python.cn
> > Subscribe: send subscribe to python-chinese-request在lists.python.cn
> > Unsubscribe: send unsubscribe to  python-chinese-request在lists.python.cn
> > Detail Info: http://python.cn/mailman/listinfo/python-chinese
>
>
>
> --
> Using Opera's revolutionary e-mail client: http://www.opera.com/mail/
>
> _______________________________________________
> python-chinese
> Post: send python-chinese在lists.python.cn
> Subscribe: send subscribe to python-chinese-request在lists.python.cn
> Unsubscribe: send unsubscribe to  python-chinese-request在lists.python.cn
> Detail Info: http://python.cn/mailman/listinfo/python-chinese
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URL: http://python.cn/pipermail/python-chinese/attachments/20061023/b28e86ed/attachment-0001.html 

ÔÚʵ²ÎÖÐͨ¹ý*ÔËËã·û½â¹¹´«µÝÒ»¸öÐòÁлòÕßͨ¹ý**ÔËËã·û´«µÝÒ»¸ö×ֵ䣬ÊÇÎÒ¾­³£×öµÄÊÂÇ飺£©¡£

2006/10/23, Leira Hua <lhua在altigen.com.cn>:
>
> ÄãËù½²½âµÄ,ÊÇÔÚÐβÎ(parameters)ÖУ¬ÕâÖÖÓ÷¨ÊÇpython±È½Ï»ù±¾µÄ¡£
> µ«ÊÇÂ¥Ö÷˵µÄÇé¿ö£¬ËƺõÊÇ*ÓÃÔÚÁËʵ²Î(arguments)ÖУ¬ËƺõÊÇ°ÑÒ»¸öÁбíÌæ»»³ÉÆä
> ¸÷¸ö³ÉÔ±ÌîÈëÐβÎÖС£ÕâÖÖÓ÷¨£¬ÎÒ»¹ÊǵÚÒ»´Î¿´µ½~
>
> ²éÁËÒ»ÏÂPython Reference Manual£¬ ÔÚ5.3.4 CallsÖУ¬¿´µ½ÁËÕâÖÖÓ÷¨£º
>
> If the syntax "*expression" appears in the function call, "expression"
> must evaluate to a sequence. Elements from this sequence are treated as if
> they were additional positional arguments; if there are postional
> arguments x1,...,xN , and "expression" evaluates to a sequence y1,...,yM,
> this is equivalent to a call with M+N positional arguments
> x1,...,xN,y1,...,yM.
>
> If the syntax "**expression" appears in the function call, "expression"
> must evaluate to a (subclass of) dictionary, the contents of which are
> treated as additional keyword arguments. In the case of a keyword
> appearing in both "expression" and as an explicit keyword argument, a
> TypeError exception is raised.
>
>
> ¶ÔÓÚÔÚº¯Êýµ÷ÓÃÖУ¬´«Èëʵ²ÎÓÐÐÎΪ*expµÄ£¬Ôòexp±ØÐëÊÇÒ»¸öÐòÁÐÀàÐÍ£¬½«expÐòÁÐ
> ÖеÄÿһ¸öÔªËØ°´Ë³ÐòÌîÈëµ½¸Ãº¯ÊýµÄÐβÎÁбíÖУº
> >>> def fun(a, b, c, d):
> ...     print a, b, c, d
> ...
> >>> li = [7,8]
> >>> fun(1,2, *li)
> 1 2 7 8
> >>>
>
> ¶ÔÓÚÔÚº¯Êýµ÷ÓÃÖУ¬´«Èëʵ²ÎÓÐÐÎΪ**expµÄ£¬Ôòexp±ØÐëÊÇÒ»¸ö×ֵ䣬½«exp×ÖµäµÄÄÚ
> ÈÝ£¬ÒԹؼü×Ö²ÎÊýµÄ·½Ê½ÌîÈ뺯ÊýµÄÐβÎÖУ¬Àý×Ó»¹ÊÇÉÏÃæµÄfun()º¯Êý£º
> >>> di = {'b':7, 'c':8}
> >>> fun(1, d=4, **di)
> 1 7 8 4
> >>>
>
>
> On Mon, 23 Oct 2006 09:58:12 +0800, amingsc
> <amingsc在gmail.com> wrote:
>
> > ¾Ù¸öÀý×Ó£¬ÏÂÃæµÄº¯Êýfun¡ÁÍê³ÉÏÔʾ²ÎÊýµÄ¹¦ÄÜ£º
> > def fun1(arg1,arg2,arg3):
> >     print arg1,arg2,arg3,
> > fun1(1,2,3)
> >
> > def fun2(args):
> >     for i in args:print i,
> > fun2([1,2,3])
> > fun2([1,2,3,4])
> >
> > def fun3(*args)
> >     for i in args:print i,
> > fun3(1,2,3,4,5)
> > fun3(1,2)
> > ±È½ÏÈý¸öº¯Êý¿ÉÒÔ¿´³ö
> > fun2±Èfun1Áé»î£¬ÒòΪfun1µÄ²ÎÊý¸öÊý¹Ì¶¨
> > fun3±Èfun2Áé»î£¬ÒòΪfun3µÄ¶à¸ö²ÎÊý¶¼²»±ØÓÃÐòÁÐÀ´´«µÝ£¬ÕâÔÚʵÏÖ²ÎÊý¸öÊý²»
> > ¶¨µÄº¯ÊýʱºÜÓÐÓã»
> >
> > ÖÁÓÚ**ÀàËÆ,Ö»ÊÇ**±íʾµÄÊÇ´ø¹Ø¼ü×ֵIJÎÊý
> > def fun4(**args):
> >     for k,v in enumerate(args):
> >        print k,v
> > fun4(id=1001,name='xx')
> > fun4(id=1001,name='xx',age=28)
> >
> > Âí̤·ÉÑà дµÀ:
> >> ´ú±íÕâ¸ö²ÎÊýÊÇÒ»¸öÁбí»òÕßÊÇÔª×é¡£
> >> 2¸öÐǺŴú±íÊÇÒ»¸ö×ֵ䡣
> >>
> >> ÔÚ 06-10-23£¬jiang hongbo<larkdream在gmail.com> дµÀ£º
> >>
> >>> ¿´µ½ÈçÏ´úÂ룬²»Ã÷°×ÕâÀï*µÄÓ÷¨£¬ËƺõÊǽ«size·Ö½âΪÀඨÒåÖеÄÁ½¸öÊôÐÔµÄ
> >>> Òâ˼£º
> >>> size = self.GetClientSize()
> >>> glViewport( 0,0, *size)            #Ï൱ÓÚglViewport( 0,0, size.width,
> >>> size.height)
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哈哈，这样的啊，俺大意了，不过其实是一回事，反正是函数进行参数传递时进行
的特殊处理罢了，这个特殊处理也就是用“*序列”来将序列解包成序列中的各个元
素，以实现形参与实参的匹配及传递，这两种情况也就是“*”操作分别出现在形参
与实参的区别啦!
FUN(*实参 ~  形参)
FUN( 实参 ~ *形参)
python不加这个*也是完全可以的，只不过加上就使得用户不需要自己编码进行解
包，用起来更省事，这正体现了python本身的宗旨－－让一切变得更简单！
例子：
def fun1(a,b,c):
    print a,b,c
def fun2(*abc):
    for i in abc:print i,

>>> fun1(*[1,2,3])
1 2 3
>>> fun1(**{'a':1,'b':2,'c':3})
1 2 3
>>> fun1(**{'a':1,'c':3,'b':2})
1 2 3

>>> fun2( 1,2,3 )
1 2 3



fdcn 写道:
> thank you
>
> On 10/23/06, *Leira Hua* <lhua at altigen.com.cn 
> lhua at altigen.com.cn>> wrote:
>
>     你所讲解的,是在形参(parameters)中，这种用法是python比较基本的。
>     但是楼主说的情况，似乎是*用在了实参(arguments)中，似乎是把一个列表
>     替换成其
>     各个成员填入形参中。这种用法，我还是第一次看到~
>
>     查了一下Python Reference Manual， 在5.3.4 Calls中，看到了这种用法：
>
>     If the syntax "*expression" appears in the function call,
>     "expression"
>     must evaluate to a sequence. Elements from this sequence are
>     treated as if
>     they were additional positional arguments; if there are postional
>     arguments x1,...,xN , and "expression" evaluates to a sequence
>     y1,...,yM,
>     this is equivalent to a call with M+N positional arguments
>     x1,...,xN,y1,...,yM.
>
>     If the syntax "**expression" appears in the function call,
>     "expression"
>     must evaluate to a (subclass of) dictionary, the contents of which
>     are
>     treated as additional keyword arguments. In the case of a keyword
>     appearing in both "expression" and as an explicit keyword argument, a
>     TypeError exception is raised.
>
>
>     对于在函数调用中，传入实参有形为*exp的，则exp必须是一个序列类型，
>     将exp序列
>     中的每一个元素按顺序填入到该函数的形参列表中：
>     >>> def fun(a, b, c, d):
>     ...     print a, b, c, d
>     ...
>     >>> li = [7,8]
>     >>> fun(1,2, *li)
>     1 2 7 8
>     >>>
>
>     对于在函数调用中，传入实参有形为**exp的，则exp必须是一个字典，将
>     exp字典的内
>     容，以关键字参数的方式填入函数的形参中，例子还是上面的fun()函数：
>     >>> di = {'b':7, 'c':8}
>     >>> fun(1, d=4, **di)
>     1 7 8 4
>     >>>
>
>
>     On Mon, 23 Oct 2006 09:58:12 +0800, amingsc
>     < amingsc at gmail.com amingsc at gmail.com>> wrote:
>
>     > 举个例子，下面的函数fun×完成显示参数的功能：
>     > def fun1(arg1,arg2,arg3):
>     >     print arg1,arg2,arg3,
>     > fun1(1,2,3)
>     >
>     > def fun2(args):
>     >     for i in args:print i,
>     > fun2([1,2,3])
>     > fun2([1,2,3,4])
>     >
>     > def fun3(*args)
>     >     for i in args:print i,
>     > fun3(1,2,3,4,5)
>     > fun3(1,2)
>     > 比较三个函数可以看出
>     > fun2比fun1灵活，因为fun1的参数个数固定
>     > fun3比fun2灵活，因为fun3的多个参数都不必用序列来传递，这在实现参
>     数个数不
>     > 定的函数时很有用；
>     >
>     > 至于**类似,只是**表示的是带关键字的参数
>     > def fun4(**args):
>     >     for k,v in enumerate(args):
>     >        print k,v
>     > fun4(id=1001,name='xx')
>     > fun4(id=1001,name='xx',age=28)
>     >
>     > 马踏飞燕 写道:
>     >> 代表这个参数是一个列表或者是元组。
>     >> 2个星号代表是一个字典。
>     >>
>     >> 在 06-10-23，jiang hongbo<larkdream at gmail.com
>     larkdream at gmail.com>> 写道：
>     >>
>     >>> 看到如下代码，不明白这里*的用法，似乎是将size分解为类定义中的
>     两个属性的
>     >>> 意思：
>     >>> size = self.GetClientSize()
>     >>> glViewport( 0,0, *size)            #相当于glViewport( 0,0,
>     size.width,
>     >>> size.height)
>     >>> 请教大家*号这种用法的意思和该用在什么地方，谢谢。
>     >>> _______________________________________________
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>     >>> Post: send python-chinese at lists.python.cn
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      谢谢大家，这么一说俺就明白了。

以前就知道*做形参的时候的用法，没想到做实参时也可以这么用。和形参的这种用法结合，可以派上不少用场啊，比C语言的不定参数用法要灵活，更加动态。
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