code: def delete(ctx, query, force):
      
  
      ensure_validated(ctx)
      controller = ctx.obj['controller']
      creds = controller.list()
      hits = _search(creds, query)
      if len(hits) == 0:
          click.echo('No matches, nothing to be done.')
      elif len(hits) == 1:
          cred = hits[0]
          if force or (click.confirm(
                  u'Delete credential: {} ?'.format(cred.printable_key),
                  default=False, err=True
          )):
              controller.delete(cred)
              click.echo(u'Deleted {}.'.format(cred.printable_key))
          else:
              click.echo('Deletion aborted by user.')
  
      else:
          _error_multiple_hits(ctx, hits)
docs: Delete a credential.
  
      Delete a credential from your YubiKey.
      Provide a query string to match the credential to delete.