Update app.py

app.py

@@ -28,7 +28,7 @@ cat_value_dicts = {}
 final_colname = uncleaned_data.columns[len(uncleaned_data.columns) - 1]
 
 # for each column...
-for (colname, colval) in uncleaned_data.iteritems():
+for (colname, colval) in uncleaned_data.items():
 
   # check if col is already a number; if so, add col directly
   # to new dataframe and skip to next column