Python pkg_resources 模块，RequirementParseError() 实例源码

def _get_cached_requirements(self):
        import os.path
        import pkg_resources

        path = os.path.join(self._cache_dir, 'requirements.txt')

        if not os.path.exists(path):
            # No cached requirements. The empty set will always trigger a cache
            # refresh because the current requirements will, at minimum,
            # contain q2cli.
            return set()
        else:
            with open(path, 'r') as fh:
                contents = fh.read()
            try:
                return set(pkg_resources.parse_requirements(contents))
            except pkg_resources.RequirementParseError:
                # Unreadable cached requirements, trigger a cache refresh.
                return set()

def version_info(module):
    """Get version of a standard python module.

    Args:
        module (module): python module object to get version info for.

    Returns:
        dict: dictionary of version info.

    """
    if hasattr(module, '__version__'):
        version = module.__version__
    elif hasattr(module, 'VERSION'):
        version = module.VERSION
    else:
        pkgname = module.__name__.split('.')[0]
        try:
            info = pkg_resources.get_distribution(pkgname)
        except (pkg_resources.DistributionNotFound, pkg_resources.RequirementParseError):
            version = None
            log.warning(
                'version information not found for %s -- what package is this from?' % module.__name__)
        else:
            version = info.version

    return {'version': version}

def check_setuptools():
    import pkg_resources
    try:
        list(pkg_resources.parse_requirements('foo;platform_system!="Windows"'))
    except pkg_resources.RequirementParseError:
        exit('Your Python is using an outdated version of `setuptools`. Please '
             'run `pip install -U setuptools` and try again.')

def _is_same_dep(cls, dep1, dep2):
        """
        Returns True if both dependency definitions refer to the
        same package, even if versions differ.
        """
        dep1_name = pkg_resources.Requirement.parse(dep1).project_name
        try:
            dep2_name = pkg_resources.Requirement.parse(dep2).project_name
        except pkg_resources.RequirementParseError:
            # we couldn't parse a version, probably a URL
            return False
        return dep1_name == dep2_name

def try_parse_requirements(lines: typed_list(str)):
        """
        Yields all package requirements parseable from the given lines.

        :param lines: An iterable of lines from a requirements file.
        """
        for line in lines:
            try:
                yield from pkg_resources.parse_requirements(line)
            except pkg_resources.RequirementParseError:
                # unsupported requirement specification
                pass

def _gen_requirements_file(self, requirements_list) -> str:
        modules = {}
        for req in requirements_list:
            name, req_spec = self._parse_line(req)

            if name is None:
                name = req

            url = None
            version = None
            try:
                # this will fail is an url is supplied
                parsed_req = list(pkg_resources.parse_requirements(req_spec))
                if len(parsed_req) > 0:
                    item = parsed_req[0]
                    if hasattr(item, "name"):
                        name = item.name
                    elif hasattr(item, "unsafe_name"):
                        name = item.unsafe_name
                    version = item.specs
                    if hasattr(item, "url"):
                        url = item.url
            except pkg_resources.RequirementParseError:
                url = req_spec

            if name not in modules:
                modules[name] = {"name": name, "version": []}

            if version is not None:
                modules[name]["version"].extend(version)

            if url is not None:
                modules[name]["url"] = url

        requirements_file = ""
        for module, info in modules.items():
            version_spec = ""
            if len(info["version"]) > 0:
                version_spec = " " + (", ".join(["%s %s" % (a, b) for a, b in info["version"]]))

            if "url" in info:
                module = info["url"]

            requirements_file += module + version_spec + "\n"

        return requirements_file