Python Decorators: timer with a Class decorator

def time_this(original_function):

print("decorating")

def new_function(*args,**kwargs):

print("starting timer")

import datetime

before = datetime.datetime.now()

x = original_function(*args,**kwargs)

after = datetime.datetime.now()

print("Elapsed Time = {0}".format(after-before))

return x

return new_function

def time_all_class_methods(Cls):

class NewCls(object):

def __init__(self,*args,**kwargs):

self.oInstance = Cls(*args,**kwargs)

def __getattribute__(self,s):

"""

this is called whenever any attribute of a NewCls object is accessed. This function first tries to

get the attribute off NewCls. If it fails then it tries to fetch the attribute from self.oInstance (an

instance of the decorated class). If it manages to fetch the attribute from self.oInstance, and

the attribute is an instance method then `time_this` is applied.

"""

try:

x = super(NewCls,self).__getattribute__(s)

except AttributeError:

pass

else:

return x

x = self.oInstance.__getattribute__(s)

if type(x) == type(self.__init__): # it is an instance method

return time_this(x) # this is equivalent of just decorating the method with time_this

else:

return x

return NewCls

#now lets make a dummy class to test it out on:

@time_all_class_methods

class Foo(object):

def a(self):

print("entering a")

import time

time.sleep(3)

print("exiting a")

def b(self):

print("entering b")

import time

time.sleep(0.5)

print("exiting b")

def c(self):

print("entering c")

import time

time.sleep(0.9)

print("exiting c")

oF = Foo()

oF.a()

oF.b()

oF.c()