Ok... it's works! :)
So what do you think?
Look at the last stacked example, it process the preprocess's first in
forward order, then does the postprocess's in reverse order. Which
might be usefull. Interesting in any case.
Making decorators with this class is a snap!
Any thoughts? Any improvements? Any bugs?
Cheers,
Ron_Adam
#---start---
class Decorator(object):
"""
Decorator - A base class to make decorators with.
self.function - the function decorated.
self.arglist - list of arguments of decorator
self.preprocess - over ride to preprocess function arguments.
self.postprocess - over ride to postprocess function
return value.
Example use:
class mydecorator(Decorate):
def self.preprocess(self, args):
# process args
return args
def self.postprocess(self, results):
# process results
return results
deco = mydecorator()
@deco
def function(args):
# function body
return args
"""
def __init__(self):
self.function = None
self.arglist = []
def __call__(self, *arg):
if len(arg) == 1:
arg = arg[0]
self.arglist.append(arg)
def _wrapper(*args):
pre_args = self.preprocess(*args)
if type(pre_args) is not tuple:
pre_args = (pre_args,)
result = self.function(*pre_args)
return self.postprocess(result)
if '<function ' in str(arg):
self.arglist = self.arglist[:-1]
self.function = arg
return _wrapper
return self
def preprocess(self, *args):
#
# Over ride this method.
#
return args
def postprocess(self, result):
#
# Over ride this method.
#
return result
#---1---
class decorator1(Decorator):
def preprocess(self, arg):
newarg = ""
n = 0
darg = list(self.arglist[0])
for a in list(arg):
newarg += a
newarg += darg[n]
n += 1
if n>=len(darg):
n = 0
return newarg
deco1 = decorator1()
@deco1('_-^-')
def test1(text):
return text
print test1('abcdefg')
# a_b-c^d-e_f-g^
#---2---
class decorator2(Decorator):
def postprocess(self, result):
result = result*1.0*self.arglist[0][0]/self.arglist[0][1]
return result
deco2 = decorator2()
@deco2(2,3)
def test2(a):
return a
print test2(7)
# 4.66666666667
#---3---
class decorator3(Decorator):
def preprocess(self, arg1, arg2):
arg1 *= 2
arg2 *= 2
return arg1, arg2
deco3 = decorator3()
@deco3
def test3(a,b):
return a,b
print test3(1,3)
# (2, 6)
#---4---
class decorator4(Decorator):
def postprocess(self, result):
result = int(result/self.arglist[0])
return result
deco4 = decorator4()
@deco4(2)
def test4(n1,n2,n3,n4,n5):
return n1+n2+n3+n4+n5
print test4(1,2,3,4,5)
# 7
#---5---
class decorator5(Decorator):
def preprocess(self, arg):
arg *= 2
print 'Preprocess:',self.arglist[0][0],arg
return arg
def postprocess(self, result):
result *= 2
print 'Postprocess:',self.arglist[0][0],result
return result
deco5a = decorator5()
deco5b = decorator5()
deco5c = decorator5()
deco5d = decorator5()
deco5e = decorator5()
@deco5a('a')
@deco5b('b')
@deco5c('c')
@deco5d('d')
@deco5e('e')
def test5(i):
return i
print test5(10)
# Preprocess: a 20
# Preprocess: b 40
# Preprocess: c 80
# Preprocess: d 160
# Preprocess: e 320
# Postprocess: e 640
# Postprocess: d 1280
# Postprocess: c 2560
# Postprocess: b 5120
# Postprocess: a 10240
# 10240
#---end---
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