from __future__ import nested_scopes
import new
def enhance_method(klass, method_name, replacement):
'替代已有的方法'
method = getattr(klass, method_name)
setattr(klass, method_name, new.instancemethod(
lambda *args, **kwds: replacement(method, *args, **kwds), None, klass))
def method_logger(old_method, self, *args, **kwds):
'给方法添加调用执行日志'
print '*** calling: %s%s, kwds=%s' % (old_method.__name__, args, kwds)
return_value = old_method(self, *args, **kwds) # call the original method
print '*** %s returns: %s' % (old_method.__name__, `return_value`)
return return_value
def demo():
class Deli:
def order_cheese(self, cheese_type):
print 'Sorry, we are completely out of %s' % cheese_type
d = Deli()
d.order_cheese('Gouda')
enhance_method(Deli, 'order_cheese', method_logger)
d.order_cheese('Cheddar')