Python-static function (Staticmethod), class function (Classmethod), member function difference (full parse)

Original address: http://blog.csdn.net/caroline_wendy/article/details/23383995

static functions (Staticmethod), class functions (Classmethod), differences in member functions (fully parsed)

Defined:

static function (@staticmethod): A static method that deals primarily with the logical association of this class, such as validating data;

class function (@classmethod): A class method that focuses more on invoking a method from a class than invoking a method in an instance, such as constructing an overload;

member function: The method of the instance, can only be called through the instance;

Code:

#-*-coding:utf-8-*-  #Eclipse Pydev, Python 3.3#by C.l.wang  classA (object): _g= 1deffoo (self,x):Print('executing foo (%s,%s)'%(self,x)) @classmethoddefClass_foo (cls,x):Print('executing Class_foo (%s,%s)'%(cls,x)) @staticmethoddefStatic_foo (x):Print('executing static_foo (%s)'%x) a=A () A.foo (1) A.class_foo (1) A.class_foo (1) A.static_foo (1) A.static_foo ('Hi')  Print(A.foo)Print(A.class_foo)Print(A.static_foo)

Output:

Executing foo (<__main__. A Object at 0x01e2e1b0>,1) executing Class_foo (<class '__main__. A'>,1) executing Class_foo (<class '__main__. A'>,1) executing Static_foo (1) executing static_foo (HI)<bound Method A.foo of <__main__. A object at 0x01e2e1b0>> <bound method Type.class_foo of <class '__main__. A'>> <function A.static_foo at 0x01e7e618>

Specific application:

For example, the date method can be instantiated (__init__) for data output;

Data conversion can be done through the class method (@classmethod) ;

Data validation can be performed by static methods (@staticmethod) ;

Code:

2. #-*-Coding:utf-8-*-
6. #eclipse Pydev, Python 3.3
8. #by C.l.wang
12. Class Date (object):
16. Day = 0
18. month = 0
20. Year = 0
24. def __init__ (self, day=0, month=0, year=0):
26. Self.day = Day
28. self.month = Month
30. Self.year = Year
34. def display (self):
36. return "{0}*{1}*{2}". Format (self.day, self.month, self.year)
40. @classmethod
42. def from_string (cls, date_as_string):
44. Day, month, year = map (int, date_as_string.split ('-'))
46. Date1 = CLS (Day, month, year)
48. return date1
52. @staticmethod
54. def is_date_valid (date_as_string):
56. Day, month, year = map (int, date_as_string.split ('-'))
58. return Day <= and month <= <= 3999
62. Date1 = Date (' one ', ' one ', ' all ')
64. Date2 = date.from_string (' 11-13-2014 ')
66. Print (Date1.display ())
68. Print (Date2.display ())
70. Print (Date2.is_date_valid (' 11-13-2014 '))
72. Print (Date.is_date_valid (' 11-13-2014 '))

Output:

12*11*2014  11*13*2014  false  false  

Reference:

Http://stackoverflow.com/questions/12179271/python-classmethod-and-staticmethod-for-beginner

Http://stackoverflow.com/questions/136097/what-is-the-difference-between-staticmethod-and-classmethod-in-python

Python-static function (Staticmethod), class function (Classmethod), member function difference (full parse)