I'm using a class

```
class Variable():
    def __init__(self, value, ratio):
    self.value = value
    self.ratio = {'A': 0.0, 'B': 0.0, 'C': 0.0}

```

and I would like to assign a value and a ratio (to one of `A`, `B` or `C`) when initializing, *i.e.*

```
> var1 = Variable(3.2, 'A'=100.0)

```

so that the outcome would be

```
> var1.value
3.2
> var1.ratio
{'A': 100.0, 'B': 0.0, 'C': 0.0}

```

Is this possible with a function argument like this, or should I use some other method?