python code mistakes

1. try, except not specific

   try:

     ....

   except:

     ....
   

this not good, ctrl+c can not stop the script, keyboard interrupt exception also handled by except.

  try:
     ....
  except Exception :
     ....

2. Get real useful exception info

     try:
      ......
    except Exception as e:
        print(e)
        or log(e)
   

   this way will get a lot of not useful or confused info

   do this:

         import traceback
   
         try:
           .........
   
         except Exception as e:
   
          traceback.print_exc()
   
         or 
              print(traceback.format_exc())
              log(tracback.format.exc())
   
   

3. Check membership

   using set instead of list

   name_lst=[.....]
   name_set={..........}
   
   if name in name_lst:
      do something
   

   this take longer time, better to do this

   if name in name_set:

         do something
   

4. use list as default parameter in fun

    def agg_name_with_lst( names, agg_lst=[]):
        ........
   
    agg_lst only create one time for many function calls
   

   do this :

     def agg_name_with_lst( names, agg_lst=None):
        if isinstance(agg_lst, type(None))
              agg_lst=list()
         else:
              do  agg