some error checking for invalid y metrics

rowers/dataprep.py

@@ -28,6 +28,7 @@ from rowingdata import (
     )
 
 from rowers.models import Team
+from rowers.metrics import axes
 
 import os
 import zipfile
@@ -899,6 +900,13 @@ def prepmultipledata(ids,verbose=False):
 # Read a set of columns for a set of workout ids, returns data as a
 # pandas dataframe
 def read_cols_df_sql(ids,columns):
+    # drop columns that are not in offical list
+    axx = [ax[0] for ax in axes]
+    for c in columns:
+        if not c in axx:
+            columns.remove(c)
+            print c,'aap'
+    
     columns = list(columns)+['distance','spm']
     columns = [x for x in columns if x != 'None']
     columns = list(set(columns))