4.5冗余参数处理

>>> def f(x):
print(x)

>>> #传递元组
>>> f(range(10))
range(0, 10)
>>> f([1,2,3,4])
[1, 2, 3, 4]
>>> #传递字典
>>> f({1:111,2:222,3:333})
{1: 111, 2: 222, 3: 333}

>>> def f(x,y):
print(x,y)

>>> t=('a','b')
>>> f(t)
Traceback (most recent call last):
File "<pyshell#94>", line 1, in <module>
f(t)
TypeError: f() missing 1 required positional argument: 'y'
>>> f(t,'test')
('a', 'b') test
>>>

#格式化字符串说明
>>> print("%s:%s"%(13,14))
13:14

>>> def f(x,y):
print("%s:%s"%(x,y))

>>> t = ('name','milo')
>>> f(t)
Traceback (most recent call last):
File "<pyshell#104>", line 1, in <module>
f(t)
TypeError: f() missing 1 required positional argument: 'y'
>>> #传递元组fun(*args)
>>> f(*t)
name:milo

>>> def f(name='name',age=0):
print("name:%s"%name)
print("age:%s"%age)

>>> f()
name:name
age:0
>>> f("milo",30)
name:milo
age:30
>>> t(30,'milo')
Traceback (most recent call last):
File "<pyshell#118>", line 1, in <module>
t(30,'milo')
TypeError: 'tuple' object is not callable
>>> t=(30,'milo')
>>> f(*t)
name:30
age:milo
>>> f(age = 30,name='milo')
name:milo
age:30
>>> #相同的实现
>>> #传递字典fun(**kwords)
>>> d = {'age':30,'name':'milo'}
>>> d
{'name': 'milo', 'age': 30}
>>> f(**d)
name:milo
age:30
>>>

>>> def f(name='name',age=0):
print("name:%s"%name)
print("age:%s"%age)

>>> #当实参和行参名称一一不对应的时候，传递字典fun(**kwords)
>>> d = {'age':30,'name':'milo'}
>>> d
{'name': 'milo', 'age': 30}
>>> f(**d)
name:milo
age:30
>>> d
{'name': 'milo', 'age': 30}
>>> d {'a':30,'n':'milo'}
SyntaxError: invalid syntax
>>> d={'a':30,'n':'milo'}
>>> f(**d)
Traceback (most recent call last):
File "<pyshell#129>", line 1, in <module>
f(**d)
TypeError: f() got an unexpected keyword argument 'n'
>>> #解决办法
>>> f(d['n'],d['a'])
name:milo
age:30
>>>

>>> def f(x,*args):
print(x)
print (args)

>>> f(1)
1
()
>>> f(1,2,3,4,5,6)
1
(2, 3, 4, 5, 6)
>>> f(x=4)
4
()
>>> #出现冗余参数
>>> #冗余参数
>>> f(x=4,y=40)
Traceback (most recent call last):
File "<pyshell#7>", line 1, in <module>
f(x=4,y=40)
TypeError: f() got an unexpected keyword argument 'y'
>>> def f(x,*args,**kwargs):
print(x)
print(*args)
print(**kwargs)

>>>#出现冗余参数的解决办法
>>> def f(x,*args,**kwargs)
SyntaxError: invalid syntax
>>> def f(x,*args,**kwargs):
print (x)
print (args)
print (kwargs)

>>> f(1)
1
()
{}
>>> f(1,2,3,4,5)
1
(2, 3, 4, 5)
{}
>>> 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 "<pyshell#23>", line 1, in <module>
f(1,2,3,4,5,6,x=10,y=20,z=30)
TypeError: f() got multiple values for argument 'x'
>>> f(1,2,3,4,5,6,y=20,z=30)
1
(2, 3, 4, 5, 6)
{'y': 20, 'z': 30}
>>>