A: default parameters of the function (the actual call, the number of arguments can be less than the number of formal parameters)
1, grammar:
def function name (parameter name argument default = 1 1 = 2 default parameter name argument 2 ......)
Example:
def info (name, age = 1.address = 'Missing'):
print (name, 'this year', age, 'old, home address is:' address)
info ( 'tarena', 15, 'Chaoyang District')
info ( 'Li', 20)
Description:
The default parameter must exist in order from right to left, if there is a default parameter argument, based on the right of all parameters must have default parameters.
The default parameters can have zero or more, or even all with default parameters.
Exercise:
MySum a write function (), arguments can be passed two or three arguments, if the incoming two arguments, two arguments and, if the incoming three arguments, the solid is returned back to the previous two ginseng and ginseng remainder of the third real results.
II: shape parameter function defined manner
1, the position parameter
grammar:
def function name (parameter 1, parameter 2, ......)
Statement block
2, the asterisk parameter tuple:
grammar:
def function name (parameter name tuple *):
Statement block
effect:
Position to collect the excess mass participation
Description:
Tuple parameter names commonly used: 'args'
Exercise:
In the system are free to enter a number, and this number is obtained, and print output.
3, named key parameter
grammar:
def function name (* named key parameter):
Statement
or
def function name (* args, name keyword parameter):
Statement
effect:
All parameters must be passed by reference parameter passing keyword or keyword dictionary transfer
Example:
4, double asterisk dictionary parameter:
grammar:
def function name (parameter name dictionary **):
Statement
effect:
Keyword collect excess mass participation
Description:
Typically dictionary parameter name as '' kwargs ''
Comprehensive:
Function parameters from left to right are: a position parameter, the asterisk parameter tuple named parameter keyword dictionary and a double asterisk parameter, the function parameters can be used in combination.
Three: the function of variable length parameters:
1, grammar:
def fn(*args, **kwargs)
pass
Description:
You can receive an arbitrary position mass participation and mass participation keywords (like how to pass on how to pass)
Exercise:
Write a myrange function, which returns a list of integers range in line with the rules.
Such as:
L = myrange (3)
Print(L)
L = myrange (3, 6)
Print(L)
说明：首先把终止值设置为None,步长为1，判断是否没有输入终止值，如果没有输入，终止值就等于开始值，初始化开始值为0，定个一个空的列表，然后绑定一个开始值，当开始值小于终止值时，把i添加到列表中，然后输出下一个i的值（i +=i + step），最后把数据传到列表里,代码如下图：
总结：
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