Return class.

Satish ML satishmlwizpro at gmail.com
Sat Jul 26 21:21:02 CEST 2014


Hi,

Which lines of code prints [4] and [4, 5, 6, 7] in the output?


Output:

CARST
Trace: display
1
Spam!Spam!Spam!Spam!Spam!Spam!Spam!Spam!
[1]
Trace: name
1
Bob
Trace: pay
2
2000

Trace: name
1
Sue
Trace: pay
2
6000
Trace: name
3
Bob
Trace: pay
4
2000
[4, 2]
INSIDE MyList
[1, 2, 3]
Trace: append
1
[4]
Trace: append
1
[4, 5, 6, 7]

Actual Code:
def Tracer(aClass):
    class Wrapper:
        def __init__(self, *args, **kargs):
            self.fetches = 0
            self.wrapped = aClass(*args, **kargs)
        def __getattr__(self, attrname):
            print('Trace: ' + attrname)
            self.fetches += 1
            print(self.fetches)
            return getattr(self.wrapped, attrname)
    return Wrapper
@Tracer
class Spam:
    def __init__(self, *args):
        print(*args)
    def display(self):
        print('Spam!' * 8)

@Tracer
class Person:
    def __init__(self, name, hours, rate):
        self.name = name
        self.hours = hours
        self.rate = rate
    def pay(self):
        return self.hours * self.rate

food = Spam("CARST")
food.display()
print([food.fetches])

bob = Person('Bob', 40, 50)
print(bob.name)
print(bob.pay())

print('')
sue = Person('Sue', rate=100, hours=60)
print(sue.name)
print(sue.pay())


Another module that is producing output:

from tracer import Tracer
@Tracer
class MyList(list):
    def __init__(self, *args):
        print("INSIDE MyList")
        print(*args)
      
x = MyList([1, 2, 3])
x.append(4)
print(x.wrapped)
WrapList = Tracer(list)
x = WrapList([4, 5, 6])
x.append(7)
print(x.wrapped)



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