Ensure `try_import` does not fail on null module.__file__

IPython/core/completerlib.py

@@ -165,7 +165,7 b' def try_import(mod: str, only_modules=False) -> List[str]:'
     except:
         return []
 
-    m_is_init = hasattr(m, '__file__') and '__init__' in m.__file__
+    m_is_init = '__init__' in (getattr(m, '__file__', '') or '')
 
     completions = []
     if (not hasattr(m, '__file__')) or (not only_modules) or m_is_init: