python 函数多实参处理

  向函数传元组和字典：f(*t) 和 f(**d)

  处理多余实参：f(x,*args,**kargs)

user1@ubuntu:~$ python
Python 2.7.3 (default, Sep 26 2013, 20:03:06) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> def f(x):
...     print x
... 
>>> f(10)
10
>>> f('hello')
hello
>>> f([1,2,3,4])
[1, 2, 3, 4]
>>> f(range(10))
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> 
>>> l = range(10)
>>> 
>>> f(l)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> f(('a','b'))
('a', 'b')
>>> f({1:111,2:222,3:333})
{1: 111, 2: 222, 3: 333}
>>> 
>>> def f(x,y):
...     print x
...     print y
... 
>>> f(1,2)
1
2
>>> f('a','b')
a
b
>>> t=('a','b')
>>> 
>>> f(t[0],t[1])
a
b
>>> f(t,'test')
('a', 'b')
test
>>> 
>>> 
>>> t = ('name','tianzhaixing')
>>> 
>>> def f(x,y):
...     print "%s : %s" % x,y
... 
>>> print "s% : s%"
s% : s%
>>> print "%s : %s" % ('name','tianzhaixing')
name : tianzhaixing
>>> def f(x,y):
...     print "%s : %s" % (x,y)
... 
>>> f(*t)                            
name : tianzhaixing
>>> tt = ('name','tianzhaixing','26')
>>> tt
('name', 'tianzhaixing', '26')
>>> def f(name="name",age=0)
  File "<stdin>", line 1
    def f(name="name",age=0)
                           ^
SyntaxError: invalid syntax
>>> def f(name="name",age=0):
...     print "name: %s" % name
...     print "age : %s" % age
... 
>>> f("tianzhaixing",26)
name: tianzhaixing
age : 26
>>> 
>>> f()
name: name
age : 0
>>> 
>>> t=(26,'tianzhaixing')
>>> f(*t)
name: 26
age : tianzhaixing
>>> d = {'name':tianzhaixing,'age':30}
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'tianzhaixing' is not defined
>>> d = {'name':'tianzhaixing','age':30}
>>> d
{'age': 30, 'name': 'tianzhaixing'}
>>> f(name="tianzhaixing",age=26)
name: tianzhaixing
age : 26
>>> f(age=26,name=
... 'tianzhaixing')
name: tianzhaixing
age : 26
>>> f(**d)
name: tianzhaixing
age : 30
>>> d['age']=27
>>> d
{'age': 27, 'name': 'tianzhaixing'}
>>> f(**d)
name: tianzhaixing
age : 27
>>> d = {'a':26,'n':'tianzhaixing'}
>>> d
{'a': 26, 'n': 'tianzhaixing'}
>>> f(**d)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: f() got an unexpected keyword argument 'a'
>>> f(d['n'],d['a'])
name: tianzhaixing
age : 26
>>> def f(x):
...     print x
... 
>>> f(1)
1
>>> 
>>> def f(x,*args):
...     print x
...     print args
... 
>>> f(1)
1
()
>>> f(1,2,3)
1
(2, 3)
>>> f(x=4,y=40)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: f() got an unexpected keyword argument 'y'
>>> def f(x,*args,**kargs):
...     print x
...     print args
...     print kargs
... 
>>> f(1)
1
()
{}
>>> f(1,2,3,4,5,6)
1
(2, 3, 4, 5, 6)
{}
>>> f(x=1)
1
()
{}
>>> f(x=1,y=2)
1
()
{'y': 2}
>>> f(1,2,3,4,5,6,x=10,y=20,z=30)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: f() got multiple values for keyword argument 'x'
>>> f(1,2,3,4,5,6,y=20,z=30)
1
(2, 3, 4, 5, 6)
{'y': 20, 'z': 30}
>>>