+ extensions = {}
+
+ if impersonate in (True, ''):
+ impersonate = ImpersonateTarget()
+ requested_targets = [
+ t if isinstance(t, ImpersonateTarget) else ImpersonateTarget.from_str(t)
+ for t in variadic(impersonate)
+ ] if impersonate else []
+
+ available_target = next(filter(self._downloader._impersonate_target_available, requested_targets), None)
+ if available_target:
+ extensions['impersonate'] = available_target
+ elif requested_targets:
+ message = 'The extractor is attempting impersonation, but '
+ message += (
+ 'no impersonate target is available' if not str(impersonate)
+ else f'none of these impersonate targets are available: "{", ".join(map(str, requested_targets))}"')
+ info_msg = ('see https://github.com/yt-dlp/yt-dlp#impersonation '
+ 'for information on installing the required dependencies')
+ if require_impersonation:
+ raise ExtractorError(f'{message}; {info_msg}', expected=True)
+ self.report_warning(f'{message}; if you encounter errors, then {info_msg}', only_once=True)
+