Linuxguy123 <linuxguy...@gmail.com> wrote:
> How do I do this in Python ?
>
> #############################
> declare A,B
>
> function getA
> return A
>
> function getB
> return B
>
> function setA(value)
> A = value
>
> function setB(value)
> B = value
>
> main()
> getA
> getB
> dosomething
> setA(aValue)
> setB(aValue)
> ############################
>
> The part I don't know to do is declare the variables, either as globals
> or as vars in a class. How is this done in Python without setting them
> to a value ?
Variables can have any value in python so if you want to pre-declare
then you set them to None normally.
As a class :-
class Stuff(object):
def __init__(self):
self.A = None
self.B = None
def getA(self):
return self.A
def getB(self):
return self.B
def setA(self, value):
self.A = value
def setB(self, value):
self.B = value
>>> a = Stuff()
>>> print a.getA()
None
>>> print a.getB()
None
>>> # dosomething
... a.setA("aValue")
>>> a.setB("aValue")
>>> print a.getA()
aValue
>>> print a.getB()
aValue
>>>
Note that in python we don't normally bother with getA/setA normally,
just use self.A, eg
class Stuff(object):
def __init__(self):
self.A = None
self.B = None
def main(self):
print self.A
print self.B
# dosomething
self.A = "aValue"
self.B = "aValue"
print self.A
print self.B
>>> a = Stuff()
>>> a.main()
None
None
aValue
aValue
>>>
If you need (later) A to be a computed value then you turn it into a
property, which would look like this. (Note the main method is
identical to that above).
class Stuff(object):
def __init__(self):
self._A = None
self.B = None
def _getA(self):
print "Getting A"
return self._A
def _setA(self, value):
print "Setting A"
self._A = value
A = property(_getA, _setA)
def main(self):
print self.A
print self.B
# dosomething
self.A = "aValue"
self.B = "aValue"
print self.A
print self.B
>>> a = Stuff()
>>> a.main()
Getting A
None
None
Setting A
Getting A
aValue
aValue
>>>
--
Nick Craig-Wood <n...@craig-wood.com> -- http://www.craig-wood.com/nick
--
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