Class decorator with class methods
I have written a class decorator that monkey-patches a class overwriting the init and adding a method persist (). So far everything OK.
Now I need to add a class method (static method) to the decorated开发者_Python百科 class. What do I have to change in my code to make staticMethod() a static method of the decorated class?
This is my code:
#! /usr/bin/env python
# -*- coding: utf-8 -*-
class Persistent (object):
def __init__ (self, table = None, rmap = None):
self.table = table
self.rmap = rmap
def __call__ (self, cls):
cls.table = self.table
cls.rmap = self.rmap
oinit = cls.__init__
def finit (self, *args, **kwargs):
print "wrapped ctor"
oinit (self, *args, **kwargs)
def persist (self):
print "insert into %s" % self.table
pairs = []
for k, v in self.rmap.items (): pairs.append ( (v, getattr (self, k) ) )
print "(%s)" % ", ".join (zip (*pairs) [0] )
print "values (%s)" % ", ".join (zip (*pairs) [1] )
def staticMethod (): print "I am static"
cls.staticMethod = staticMethod
cls.__init__ = finit
cls.persist = persist
return cls
@Persistent (table = "tblPerson", rmap = {"name": "colname", "age": "colage"} )
class Test (object):
def __init__ (self, name, age):
self.name = name
self.age = age
a = Test ('John Doe', '23')
a.persist ()
Test.staticMethod ()
And the output is:
wrapped ctor
insert into tblPerson
(colage, colname)
values (23, John Doe)
Traceback (most recent call last):
File "./w2.py", line 39, in <module>
Test.staticMethod ()
TypeError: unbound method staticMethod() must be called with Test instance as first argument (got nothing instead)
@staticmethod
def staticMethod (): print "I am static"
or
def staticMethod (): print "I am static"
cls.staticMethod = staticmethod(staticMethod)
use the @staticmethod decorator.
@staticmethod
def staticMethod() : ...
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