code: def flatten_dict(i):
      
  
      prefix='#'
      if i.get('prefix','')!='': prefix=str(i['prefix'])
  
      a=i['dict']
      aa={}
  
      pk=i.get('prune_keys','')
      if pk=='': pk=[]
  
      flatten_dict_internal(a, aa, prefix, pk)
  
      return {'return':0, 'dict': aa}
docs: Any list item is converted to @number=value
      Any dict item is converted to #key=value
      # is always added at the beginning 
  
      Input:  {
                dict         - python dictionary
  
                (prefix)     - prefix (for recursion)
  
                (prune_keys) - list of keys to prune (can have wildcards)
              }
  
      Output: {
                return  - return code =  0, if successful
                                      >  0, if error
                (error) - error text if return > 0
                dict    - flattened dictionary
              }