Python Custom class

1.__str__

class Student (object):     def __init__ (self, name):         == Student ("Michael")print m

<__main__. Student Object at 0x0000000003280ef0>

To make the result format of the print class easier to read

Rewrite __str__ (self)

class Student (object):     def __init__ (self, name):         = name            def__str__(self):        return"  Student Name is%s! "%= Student ("Michael")print m

 is Michael!

__repr__ similar to __str__, different __repr__ mainly use the interaction with the developer

2.__iter__

To change a class to an iterative type

classFib (object):def __init__(self): SELF.A=0 self.b= 1def __iter__(self):return SelfdefNext (self): SELF.A, self.b= self.b, SELF.A +self.bifSELF.A > 100:            Raisestopiteration ()returnSELF.A forNinchFib ():PrintN

3.__getitem__

For iterations, you can use array subscripts to access the variables

classFib (object):def __init__(self): SELF.A=0 self.b= 1def __iter__(self):return SelfdefNext (self): SELF.A, self.b= self.b, SELF.A +self.bifSELF.A > 100:            Raisestopiteration ()returnSELF.Adef __getitem__(self, item): forIinchRange (item): SELF.A, self.b= self.b, SELF.A +self.breturnSELF.APrintFib () [11]

4.__getattr__

Directly on the example:

classPerson (object):def __init__(self): Self.name="Michael"    def __getattr__(self, item):ifitem = =" Age": Self.age= 22returnSelf.agem=Person ()PrintM.__getattr__(" Age")

Attach a code that dynamically generates a path

classClain (object):def __init__(Self, path=""): Self._path=Pathdef __getattr__(self, item):returnClain ("%s/%s"%(Self._path, item))def __str__(self):returnSelf._pathPrintClain (). Usr.bin.env.python

/usr/bin/env/python

5.__call__

Invoking instances directly

Last Example:

class Person (object):     def __init__ (self):         " Michael "    def __call__ (Self, *args, * *Kwargs)        : Print " My name is%s " % self.name        = Person () m ()

 is Michael

Attached: __getattr__ and __call__ Federated calls

classClain (object):def __init__(Self, path=""): Self._path=Pathdef __getattr__(self, item):returnClain ("%s/%s"%(Self._path, item))def __str__(self):returnSelf._pathdef __call__(Self, *args, * *Kwargs): forIinchArgs:self._path="%s/%s"%(Self._path, i)returnClain (Self._path)PrintClain (). USR ("Michael"). Bin.env.python

/usr/michael/bin/env/python

Python Custom class