Fix(ImportManager): Use cache_from_source to find byte-code files

Cheetah/ImportManager.py

@@ -21,7 +21,8 @@
 import py_compile
 import sys
 from .compat import PY2, string_type, new_module, get_suffixes, \
-    load_module_from_file, ModuleNotFoundError, RecursionError
+    load_module_from_file, cache_from_source, \
+    ModuleNotFoundError, RecursionError
 if PY2:
     import imp
 else:
@@ -192,7 +193,10 @@ def getmod(self, nm, getsuffixes=get_suffixes,
         py = pyc = None
         for pth, ispkg, pkgpth in possibles:
             for ext, mode, typ in getsuffixes():
-                attempt = pth + ext
+                if typ == 2:  # imp.PY_COMPILED
+                    attempt = cache_from_source(pth + '.py')
+                else:
+                    attempt = pth + ext
                 try:
                     st = _os_stat(attempt)
                 except Exception:
@@ -202,8 +206,10 @@ def getmod(self, nm, getsuffixes=get_suffixes,
                         return load_module_from_file(nm, nm, attempt)
                     elif typ == 1:  # imp.PY_SOURCE
                         py = (attempt, st)
-                    else:
+                    elif typ == 2:  # imp.PY_COMPILED
                         pyc = (attempt, st)
+                    else:
+                        raise ValueError("Unknown module type %d" % typ)
             if py or pyc:
                 break
         if py is None and pyc is None:

Cheetah/compat.py

@@ -37,6 +37,16 @@ def load_module_from_file(base_name, module_name, filename):
     new_module = imp.new_module
     get_suffixes = imp.get_suffixes
 
+    def cache_from_source(path, debug_override=None):
+        assert path.endswith('.py'), path
+        if debug_override is None:
+            debug_override = __debug__
+        if debug_override:
+            suffix = 'c'
+        else:
+            suffix = 'o'
+        return path + suffix
+
 else:
     import importlib.machinery
     import importlib.util
@@ -59,3 +69,5 @@ def get_suffixes():
         ]
 
         return extensions + source + bytecode
+
+    from importlib.util import cache_from_source  # noqa: F401 unused

docs/news.rst

@@ -11,6 +11,9 @@ Bug fixes:
 
   - Fixed absolute import in ``ImportHooks`` under Python 3.
 
+  - Use ``cache_from_source`` in ``ImportManager`` to find out
+    ``.pyc``/``.pyo`` byte-code files.
+
   - Fixed ``Template.webInput``: Use ``urllib.parse.parse_qs``
     instead of ``cgi.FieldStorage``; Python 3.13 dropped ``cgi``.