fixes

rowers/dataprep.py

@@ -539,7 +539,10 @@ def setcp(workout, background=False, recurrance=True):
             if df['delta'][0] in tarr:
                 return(df, df['delta'], df['cp'])
     except Exception as e:
-        pass
+        try:
+            os.remove(filename)
+        except:
+            pass
 
     strokesdf = read_data(
         ['power', 'workoutid', 'time'], ids=[workout.id])
@@ -597,9 +600,8 @@ def setcp(workout, background=False, recurrance=True):
         })
         
         df = df.drop_nulls()
+        df.write_parquet(filename,compression='gzip')
 
-        with gzip.open(filename, 'w') as f:
-            df.write_parquet(f)
     except Exception as e:
         dologging("metrics.log", "setcp: "+ str(e))
         return pl.DataFrame({'delta': [], 'cp': []}), pl.Series(dtype=pl.Float64), pl.Series(dtype=pl.Float64)