Fixed PEP8 violations in dataset_loader.py
Fixed PEP8 violations in dataset_loader.py

lewismc/climate,lewismc/climate,apache/climate,huikyole/climate,Omkar20895/climate,jarifibrahim/climate,Omkar20895/climate,lewismc/climate,agoodm/climate,jarifibrahim/climate,huikyole/climate,agoodm/climate,apache/climate,jarifibrahim/climate,Omkar20895/climate,huikyole/climate,apache/climate,agoodm/climate,Omkar20895/climate,lewismc/climate,agoodm/climate,huikyole/climate,apache/climate,apache/climate,huikyole/climate,Omkar20895/climate,agoodm/climate,jarifibrahim/climate,lewismc/climate,jarifibrahim/climate