def _check_ne_builtin_clash(expr):
 names = expr.names
 overlap = (names & _ne_builtins)
 if overlap:
  s = ', '.join(map(repr, overlap))
  raise NumExprClobberingError(('Variables in expression "%s" overlap with builtins: (%s)' % (expr, s)))

def _check_ne_builtin_clash ( expr ) : names = expr . names overlap = ( names & _ne_builtins ) if overlap : s = ', ' . join ( map ( repr , overlap ) ) raise NumExprClobberingError ( ( 'Variables in expression "%s" overlap with builtins: (%s)' % ( expr , s ) ) )
attempt to prevent foot-shooting in a helpful way .