Is this considered pythonic?

```
class Solution(object):
def letterCombinations(self, digits):
if not digits:
return []
results = ['']
map = {'2':'abc', '3':'def', '4':'ghi', '5':'jkl', '6':'mno', '7':'pqrs', '8':'tuv', '9':'wxyz'}
for digit in digits:
results = [result+d for result in results for d in map[digit]]
return results
```