code: def verify_attr_existence(self, table_name, attr_name):
          
  
          self.verify_table_existence(table_name)
  
          if self.has_attr(table_name, attr_name):
              return
  
          raise AttributeNotFoundError(
              "'{}' attribute not found in '{}' table".format(attr_name, table_name)
          )
docs: :param str table_name: Table name that the attribute exists.
          :param str attr_name: Attribute name to tested.
          :raises simplesqlite.AttributeNotFoundError:
              If attribute not found in the table
          :raises simplesqlite.TableNotFoundError:
              |raises_verify_table_existence|
  
          :Sample Code:
              .. code:: python
  
                  from simplesqlite import (
                      SimpleSQLite,
                      TableNotFoundError,
                      AttributeNotFoundError
                  )
  
                  table_name = "sample_table"
                  con = SimpleSQLite("sample.sqlite", "w")
                  con.create_table_from_data_matrix(
                      table_name,
                      ["attr_a", "attr_b"],
                      [[1, "a"], [2, "b"]])
  
                  con.verify_attr_existence(table_name, "attr_a")
                  try:
                      con.verify_attr_existence(table_name, "not_existing")
                  except AttributeNotFoundError as e:
                      print(e)
                  try:
                      con.verify_attr_existence("not_existing", "attr_a")
                  except TableNotFoundError as e:
                      print(e)
          :Output:
              .. parsed-literal::
  
                  'not_existing' attribute not found in 'sample_table' table
                  'not_existing' table not found in /tmp/sample.sqlite