code: def load_schema(filename, context=None):
      
      table = import_from_uri(filename)
      field_names = table.field_names
      assert "field_name" in field_names
      assert "field_type" in field_names
  
      context = context or {
          key.replace("Field", "").lower(): getattr(rows.fields, key)
          for key in dir(rows.fields)
          if "Field" in key and key != "Field"
      }
      return OrderedDict(
          [
              (row.field_name, context[row.field_type])
              for row in table
          ]
      )
docs: Load schema from file in any of the supported formats
  
      The table must have at least the fields `field_name` and `field_type`.
      `context` is a `dict` with field_type as key pointing to field class, like:
          {"text": rows.fields.TextField, "value": MyCustomField}