Creating class instance properties from a dictionary?

You can also use dict.update instead of manually looping over items (and if you're looping, iteritems is better).

class allMyFields(object):
    # note: you cannot (and don't have to) use self here
    Field1 = None
    Field2 = None

    def __init__(self, dictionary):
        self.__dict__.update(dictionary)

q = { 'Field1' : 3000, 'Field2' : 6000, 'RandomField' : 5000 }
instance = allMyFields(q)

print instance.Field1      # => 3000
print instance.Field2      # => 6000
print instance.RandomField # => 5000

>>> q = { 'Field1' : 3000, 'Field2' : 6000, 'RandomField' : 5000 }
>>> q = type('allMyFields', (object,), q)
>>> q.Field1
3000

docs for type explain well what's going here (see use as a constructor).

edit: in case you need instance variables, the following also works:

>>> a = q()             # first instance
>>> a.Field1
3000
>>> a.Field1 = 1
>>> a.Field1
1
>>> q().Field1           # second instance
3000

You can use setattr (be careful though: not every string is a valid attribute name!):

>>> class AllMyFields:
...     def __init__(self, dictionary):
...         for k, v in dictionary.items():
...             setattr(self, k, v)
... 
>>> o = AllMyFields({'a': 1, 'b': 2})
>>> o.a
1

Edit: let me explain the difference between the above code and SilentGhost's answer. The above code snippet creates a class of which instance attributes are based on a given dictionary. SilentGhost's code creates a class whose class attributes are based on a given dictionary.

Depending on your specific situation either of these solutions may be more suitable. Do you plain to create one or more class instances? If the answer is one, you may as well skip object creation entirely and only construct the type (and thus go with SilentGhost's answer).