浅析python参数的知识点

In [8]: def num():

 ...:  a=12 

 ...:  b=23

 ...:  c=a+b

 ...:  print(c)

In [10]: def num1(a):

 ....:  print(a)

 ....:  In [11]: def num2(a,b):

 ....:  c=a+b

 ....:  print(c)

 ....:  In [12]: def num3(a,b,c):

 ....:  d=a+b+c

 ....:  print(d)

In [13]: def num2(a,b):

 ....:  c=a+b

 ....:  print(c)

 ....:  

In [14]: 

In [14]: num2(1,2)

3

In [18]: def info(name,age=20):

 ....:  print("name:",name)

 ....:  print("age:",age)

 ....:  In [19]: info(name='zcf')

name: zcf

age: 20

In [20]: info(age=21,name='zcf')

name: zcf

age: 21

In [21]: def info(name,age=20,sex):

 ....:  print(name)

 ....:  

 File "<ipython-input-21-099520322ee2>", line 1

 def info(name,age=20,sex):

   ^

SyntaxError: non-default argument follows default argument

def functionname([formal_args,] *args,**kwargs):

  function_suite

  return [expression]