I was just wondering if anyone knew of a way to change variable names based off of a for loop for something like this:
for i in range(3)
group+i=self.getGroup(selected, header+i)
so that the names of the variables change to accomodate the data. Thanks!
~Sam
You probably want a dict instead of separate variables. For example
d = {}
for i in range(3):
d["group" + str(i)] = self.getGroup(selected, header+i)
If you insist on actually modifying local variables, you could use the locals function:
for i in range(3):
locals()["group"+str(i)] = self.getGroup(selected, header+i)
On the other hand, if what you actually want is to modify instance variables of the class you're in, then you can use the setattr function
for i in group(3):
setattr(self, "group"+str(i), self.getGroup(selected, header+i)
And of course, I'm assuming with all of these examples that you don't just want a list:
groups = [self.getGroup(i,header+i) for i in range(3)]
Use a list.
groups = [0]*3
for i in xrange(3):
groups[i] = self.getGroup(selected, header + i)
or more "Pythonically":
groups = [self.getGroup(selected, header + i) for i in xrange(3)]
For what it's worth, you could try to create variables the "wrong" way, i.e. by modifying the dictionary which holds their values:
l = locals()
for i in xrange(3):
l['group' + str(i)] = self.getGroup(selected, header + i)
but that's really bad form, and possibly not even guaranteed to work.
Definitely should use a dict using the "group" + str(i) key as described in the accepted solution but I wanted to share a solution using exec. Its a way to parse strings into commands & execute them dynamically. It would allow to create these scalar variable names as per your requirement instead of using a dict. This might help in regards what not to do, and just because you can doesn't mean you should. Its a good solution only if using scalar variables is a hard requirement:
l = locals()
for i in xrange(3):
exec("group" + str(i) + "= self.getGroup(selected, header + i)")
Another example where this could work using a Django model example. The exec alternative solution is commented out and the better way of handling such a case using the dict attribute makes more sense:
Class A(models.Model):
....
def __getitem__(self, item): # a.__getitem__('id')
#exec("attrb = self." + item)
#return attrb
return self.__dict__[item]
It might make more sense to extend from a dictionary in the first place to get setattr and getattr functions.
A situation which involves parsing, for example generating & executing python commands dynamically, exec is what you want :) More on exec here.
It looks like you want to use a list instead:
group=[]
for i in range(3):
group[i]=self.getGroup(selected, header+i)
You could access your class's __dict__ attribute:
for i in range(3)
self.__dict__['group%d' % i]=self.getGroup(selected, header+i)
But why can't you just use an array named group?
