capybara/virtualenv/lib/python2.7/site-packages/pip/index.py
def _get_pages(self, locations, project_name):
        """
        Yields (page, page_url) from the given locations, skipping
        locations that have errors, and adding download/homepage links
        """
        all_locations = list(locations)
        seen = set()
        normalized = normalize_name(project_name)

        while all_locations:
            location = all_locations.pop(0)
            if location in seen:
                continue
            seen.add(location)

            page = self._get_page(location)
            if page is None:
                continue

            yield page

            for link in page.rel_links():

                if (normalized not in self.allow_external and not
                        self.allow_all_external):
                    self.need_warn_external = True
                    logger.debug(
                        "Not searching %s for files because external "
                        "urls are disallowed.",
                        link,
                    )
                    continue

                if (link.trusted is not None and not
                        link.trusted and
                        normalized not in self.allow_unverified):
                    logger.debug(
                        "Not searching %s for urls, it is an "
                        "untrusted link and cannot produce safe or "
                        "verifiable files.",
                        link,
                    )
                    self.need_warn_unverified = True
                    continue

                all_locations.append(link)
def _get_pages(self, locations, project_name):
        """
        Yields (page, page_url) from the given locations, skipping
        locations that have errors, and adding download/homepage links
        """
        all_locations = list(locations)
        seen = set()
        normalized = normalize_name(project_name)

        while all_locations:
            location = all_locations.pop(0)
            if location in seen:
                continue
            seen.add(location)

            page = self._get_page(location)
            if page is None:
                continue

            yield page

            for link in page.rel_links():

                if (normalized not in self.allow_external and not
                        self.allow_all_external):
                    self.need_warn_external = True
                    logger.debug(
                        "Not searching %s for files because external "
                        "urls are disallowed.",
                        link,
                    )
                    continue

                if (link.trusted is not None and not
                        link.trusted and
                        normalized not in self.allow_unverified):
                    logger.debug(
                        "Not searching %s for urls, it is an "
                        "untrusted link and cannot produce safe or "
                        "verifiable files.",
                        link,
                    )
                    self.need_warn_unverified = True
                    continue

                all_locations.append(link)
Yields (page, page_url) from the given locations, skipping
        locations that have errors, and adding download/homepage links