converters.py
24 lines
| 531 B
| text/x-python
|
PythonLexer
Siddharth Agarwal
|
r34398 | """ | ||
| Commonly useful converters. | ||||
| """ | ||||
| from __future__ import absolute_import, division, print_function | ||||
| def optional(converter): | ||||
| """ | ||||
| A converter that allows an attribute to be optional. An optional attribute | ||||
| is one which can be set to ``None``. | ||||
| :param callable converter: the converter that is used for non-``None`` | ||||
| values. | ||||
| .. versionadded:: 17.1.0 | ||||
| """ | ||||
| def optional_converter(val): | ||||
| if val is None: | ||||
| return None | ||||
| return converter(val) | ||||
| return optional_converter | ||||