python 验证数据类型函数

在查看谷歌API类时发现这个函数，发现有问题,先上原函数:

def ValidateTypes(vars_tpl):
  """Checks that each variable in a set of variables is the correct type.

  Args:
    vars_tpl: A tuple containing a set of variables to check.

  Raises:
    ValidationError: The given object was not one of the given accepted types.
  """
  for var, var_types in vars_tpl:
    if not isinstance(var_types, tuple):
      var_types = (var_types,)
    for var_type in var_types:
      if isinstance(var, var_type):
        return
    msg = ('The \'%s\' is of type %s, expecting one of %s.'
           % (var, type(var), var_types))
    raise ValidationError(msg)


 d = {'d':1}
 e = (1,2,3)
 ValidateTypes(((d, dict), (e, list)))

代码通过验证，本来e是tuple,用来验证的类是list,应该抛错才对，因为15行那里用了return返回，所以后面的验证不再进行。

修改后的函数如下：

def ValidateTypes(vars_tpl):
  """Checks that each variable in a set of variables is the correct type.

  Args:
    vars_tpl: A tuple containing a set of variables to check.

  Raises:
    ValidationError: The given object was not one of the given accepted types.
  """
  if not isinstance(vars_tpl, tuple):
    raise ValidationError("vars_tpl argument must be tuple")
  for var, var_types in vars_tpl:
    if not isinstance(var_types, tuple):
      var_types = (var_types,)
    msg = ('The \'%s\' is of type %s, expecting one of %s.'
           % (var, type(var), var_types))

    for var_type in var_types:
      if not isinstance(var, var_type):
        raise ValidationError(msg)

能正确地抛出异常：

这个函数非常灵活，以后项目中能用上的地方非常多，呵呵~