了解 Pycharm 推断类型提示

Question

我想通过快速文档 window 中的推断类型了解 PyCharm 中发生的事情 window。

使用下面的函数，我在快速文档中看到以下内容：

参数 host 如我所料显示为 Optional[str]，但 auth 和 version 仅显示 str | None。从技术上讲（我相信）两者都是正确的，但为什么这些相似的论点之间存在差异？

您会注意到我尝试更改版本的类型提示只是为了看看是否有任何不同。

我是否遗漏了类型提示的工作原理？
有什么方法可以让 Optional[str] 显示 auth 和 version 吗？

def getBaseUrl(service, host=None, auth=None, version=None):
    """
    Defaulted arguments will automatically fetch the values from config 

    :param str service: wms, wfs
    :param str or None host:    [internal | external | {user submitted host}] -
                                internal and external will use the config file to automatically determine
                                anything else will be assumed as a server address including possible port.
    :param str or None auth:    basic, digest, oauth 
                                anything else will raise exception
    :param version: eg wms_v1, wfs_v1
    :type version:  str or None
    :return: base url for use in the gis Webservice
    """
    assert service.lower() == 'wms' or service.lower() == 'wfs', "Unsupported service: %s" % service

    internalhost = cfg.get('GIS', 'internalhost')
    externalhost = cfg.get('GIS', 'externalhost')

    if host is None:
        host = cfg.get('GIS', 'host')
    if version is None:
        version = cfg.get(service, 'version')

    if host == "internal":
        host = "{host}".format(host=internalhost)

    elif host == 'external':
        host = "{host}".format(host=externalhost)

    else:
        host = "{host}".format(host=host)

    return buildBaseUrl(host=host, version=version, auth=auth, service=service)

Answer 1

看起来这确实是 Pycharm 的一个错误。将在 2016.2 版本中修复。

https://youtrack.jetbrains.com/issue/PY-17705

了解 Pycharm 推断类型提示

Understanding Pycharm inferred type hinting

python

type-hinting

pycharm

python-2.7