C ++ ape's Python note 03-Function

Basic Data Type Integer, long integer, floating point, plural, string

 

Variable

You do not need to declare or define a type. You can assign a value when needed.

 

Function Definition

Def function name (parameter list)

You do not need to declare or define the type when using a variable. Therefore, the function does not need to define the return type.

By default, none is returned.

 

Notes for Functions

1. the parameter is a value transfer

2. assign values to external variables and use the global keyword

Def Func (x ):
Print   ' X is ' , X
X =   2
Print   ' Changed local X ' , X
X =   50
Func (X)
Print   ' Value of X is ' , X

3. Support for default parameters

Def Say (message, times =   1 ):
Print Message * Times
Say ( ' Hello ' )
Say ( ' World ' , 5 )

4. Key parameters are supported. That is, the parameter of the specified real parameter.

Def Func (a, B = 5 , C = 10 ):
Print   ' A is ' ,, ' And B is ' , B, ' And C is ' , C
Func ( 3 , 7 )
Func ( 25 , C = 24 )
Func (C = 50 , = 100 )

Output

>>>  
A Is   3   And B Is   7   And C Is   10
A Is   25   And B Is   5   And C Is   24
A Is   100   And B Is   5   And C Is   50
>>>  

5. Pass indicates an empty statement block.

Def Somefunction ():
Pass

6. docstrings

If the first logical line after function definition is a string, it is the document string of this function.

The description statement that can be called. The call method isFunction name. _ Doc __

The document string convention is:

A multi-line string whose first line starts with an uppercase letter and ends with a full stop.

The second line is empty,

The detailed description starts from the third line. 

Def Printmax (x, y ):
''' This is docstrings.

Return Max number.'''
X = INT (X) # Convert to integers, if possible
Y = INT (y)
If X > Y:
Print X, ' Is maximum '
Else :
Print Y, ' Is maximum '
Printmax ( 3 , 5 )
Print Printmax. _ Doc __