unused variable "datatype"?

my IDE is pointing out that `datatype` is never used, and so this whole block has no real effect, I think?:
```
datatype = None
if 'datatype' not in self.request.data:
if self.request.data['filetype'] == 'cooler':
datatype = 'matrix'
elif self.request.data['filetype'] == 'hitile':
datatype = 'vector'
else:
raise rfe.APIException('Missing datatype. Could not infer from filetype:', self.request.data['filetype'])
```
Not sure whether it's vestigial, or if that field should be used? Also, do you have strong feelings about static code analysis tools? Refinery is using flake8, I think.