# Compute the product of 3 dictionaries and concatenate keys and values

The function that will do the job is `itertools.product`

.
First, here is how you can print out the product `dict1 x dict2 x dict3`

:

```
for t in product(dict1.items(), dict2.items(), dict3.items()):
k, v = zip(*t)
print("_".join(k), "-", " and ".join(v))
```

Output:

```
A_B_F - a and b and f
A_B_G - a and b and g
A_C_F - a and c and f
A_C_G - a and c and g
A_D_F - a and d and f
A_D_G - a and d and g
A_E_F - a and e and f
A_E_G - a and e and g
```

Now, just populate a `result`

dictionary:

```
result = {}
for t in product(dict1.items(), dict2.items(), dict3.items()):
k, v = zip(*t)
result["_".join(k)] = " and ".join(v)
```

You can now add to this dictionary the `dict1 x dict2`

and `dict1 x dict3`

products, that are even simpler to compute.

Based on @ShadowRanger's comment, here is a complete snippet:

```
import itertools
import pprint
dict1 = {
"A": "a"
}
dict2 = {
"B": "b",
"C": "c",
"D": "d",
"E": "e"
}
dict3 = {
"F": "f",
"G": "g"
}
result = {}
for dicts in ((dict1, dict2), (dict1, dict3), (dict1, dict2, dict3)):
for t in itertools.product(*(d.items() for d in dicts)):
k, v = zip(*t)
result["_".join(k)] = " and ".join(v)
pprint.pprint(result)
```

Output:

```
{'A_B': 'a and b',
'A_B_F': 'a and b and f',
'A_B_G': 'a and b and g',
'A_C': 'a and c',
'A_C_F': 'a and c and f',
'A_C_G': 'a and c and g',
'A_D': 'a and d',
'A_D_F': 'a and d and f',
'A_D_G': 'a and d and g',
'A_E': 'a and e',
'A_E_F': 'a and e and f',
'A_E_G': 'a and e and g',
'A_F': 'a and f',
'A_G': 'a and g'}
```