I have three dictionaries with similar keys, whose values i would like to do some computing with.

```
dict1 = {key1: 1, key2: 2, key3: 3}
dict2 = {key1: 10, key2: 10, key3: 10}
dict2 = {key1: 1, key2: 2, key3: 3}

```

How can I use python to find a dictionary with the result of:

```
dict1.values() / ((dict2.values() - dict3.values())*100)

```

i'm looking for the result like so:

```
resultdict = {key1: .00111111, key2: .0025, key3: .00428571}

```

I had succeeded in doing a calculation with two dictionaries in the following way, but I'm confused about how to include a third:

```
finaldict = {}
for key in (dict1.viewkeys() | dict2.viewkeys()):
    if key in dict1: finaldict.setdefault(key, []).append(dict1[key][0])
    if key in dict2: finaldict.setdefault(key, []).append(dict2[key])
for lst in finaldict.values():
    if not lst[0] == 0:
        lst[0] = (float(lst[1]) / float(lst[0]))*100
        del lst[-1]

```