[web2py] Check for a value in a table

[Hassan Alnatour]

Dear ALL ,

How can a check if a value for a Field in a table , now in this i do this 

values = []
for i in db().select(db.table.ALL): 
   values.append(i.Field)

then i check like this :
  if i in values:
      . .........


Is there a better way to do this ??

Best Regards,

--