feat: More robust survey preprocessing

coordinator/ProcessorSurveyUtils.py

@@ -74,10 +74,17 @@ def parse_date(series,name_out='date',fmt_in = '%Y-%m-%d',fmt_out= '%b %d, %Y'):
 
     return s_out
 
-def parse_cases(series, name_out, cases, dtype = None):
+def parse_cases(series, name_out, cases, dtype = None, fillna = None):
+    
     if dtype is None:
         dtype = series.dtype
+
+    # Handle nans explicitly
+    if fillna is not None:
+        series.fillna(fillna,inplace=True)
+
     # Converting entries according to a cases dictionary
+    # nans cannot be handled by map
     series_out = series.map(cases).astype(dtype)
     
     # Renaming series