Special methods for classes in Python

This article shares with you the main is python The special method of the class in the language related usage, hope to be helpful to everybody.

　　Construct a sequence

　　1._len_ (self)

　　2._getitem_ (Self,key)

　　3._setitem_ (Self,key,value)

　　4._delitem_ (Self,key)

　　Program Demo:

　　myseq.py

　　Class Myseq:

　　def __init__ (self):

　　Self.lseq = ["I", "II", "III", "IV"]

　　def __len__ (self):

　　Return Len (SELF.LSEQ)

　　def __getitem__ (Self,key):

　　If 0 <= key < 4:

　　return Self.lseq[key]

　　if __name__ = = ' __main__ ':

　　m = Myseq ()

　　For I in range (4):

　　Print (M[i])

　　The running result of the program is:

　　Construction of ITER

　　1._iter_ (self)

　　2._next_ (self)

　　The program demonstrates the following:

　　Class Myiter:

　　def __init__ (self,start,end):

　　Self.count = Start

　　Self.end = End

　　def __iter__ (self):

　　return self

　　def __next__ (self):

　　If Self.count < self.end:

　　r = Self.count

　　Self.count + = 1

　　Return r

　　Else

　　Raise Stopiteration

　　if __name__ = = ' __main__ ':

　　For I in Myiter (1,10):

　　Print (i)

　　The running result of the program is:

　　Constructing comparable classes

　　1._it_()

　　2._le_ ()

　　3._gt_ ()

　　4._ge_ ()

　　5._eq_ ()

　　6._ne_ ()

　　The program demonstrates the following:

　　mycmp.py

　　Class Myiter:

　　def __init__ (self,start,end):

　　Self.count = Start

　　Self.end = End

　　def __iter__ (self):

　　return self

　　def __next__ (self):

　　If Self.count < self.end:

　　r = Self.count

　　Self.count + = 1

　　Return r

　　Else

　　Raise Stopiteration

　　if __name__ = = ' __main__ ':

　　For I in Myiter (1,10):

　　Print (i)

　　The running result of the program is:

　　Constructing an operational class

　　1._add_ ()

　　2._sub_ ()

　　3._mul_ ()

　　4._div_ ()

　　The program demonstrates the following:

　　Class point:

　　def __init__ (self,x,y):

　　self.x = X

　　Self.y = y

　　def __add__ (Self,oth):

　　Return point (self.x + oth.x, Self.y + oth.y)

　　def info (self):

　　Print (SELF.X,SELF.Y)

　　if __name__ = = ' __main__ ':

　　PA = point (from)

　　PB = Point (3,4)

　　PC = PA + PB

　　Pc.info ()

　　The running result of the program is:

original link:http://www.maiziedu.com/wiki/python/special/

Special methods for classes in Python