Split out formatting of class names into a common method that supports stripping.

diffoscope/comparators/utils/file.py

@@ -30,7 +30,7 @@ from diffoscope.exc import (
     ContainerExtractionError,
 )
 from diffoscope.tools import tool_required
-from diffoscope.utils import format_cmdline
+from diffoscope.utils import format_cmdline, format_class
 from diffoscope.config import Config
 from diffoscope.profiling import profile
 from diffoscope.difference import Difference
@@ -237,9 +237,6 @@ class File(metaclass=abc.ABCMeta):
                 return self._other_file.__class__.CONTAINER_CLASSES[0](self)
             return None
 
-        def type_name(klass):
-            return "{}.{}".format(klass.__module__, klass.__name__)
-
         if hasattr(self, "_as_container"):
             return self._as_container
 
@@ -248,20 +245,24 @@ class File(metaclass=abc.ABCMeta):
         # Try each container class in turn, returning the first one that
         # instantiates without error.
         for klass in klasses:
+            formatted_class = format_class(
+                klass, strip="diffoscope.comparators."
+            )
+
             logger.debug(
-                "Instantiating a %s for %s", type_name(klass), self.name,
+                "Instantiating a %s for %s", formatted_class, self.name,
             )
             try:
                 self._as_container = klass(self)
 
                 logger.debug(
-                    "Returning a %s for %s", type_name(klass), self.name,
+                    "Returning a %s for %s", formatted_class, self.name,
                 )
                 return self._as_container
             except RequiredToolNotFound as exc:
                 logger.debug(
                     "Cannot instantiate a %s; missing tool %s",
-                    type_name(klass),
+                    formatted_class,
                     exc.command,
                 )
                 try:

diffoscope/comparators/utils/specialize.py

@@ -21,6 +21,8 @@ import logging
 
 from diffoscope.profiling import profile
 
+from ...utils import format_class
+
 from .. import ComparatorManager
 
 logger = logging.getLogger(__name__)
@@ -37,7 +39,11 @@ def try_recognize(file, cls, recognizes):
             return False
 
     # Found a match; perform type magic
-    logger.debug("Using %s.%s for %s", cls.__module__, cls.__name__, file.name)
+    logger.debug(
+        "Using %s for %s",
+        format_class(cls, strip="diffoscope.comparators."),
+        file.name,
+    )
     new_cls = type(cls.__name__, (cls, type(file)), {})
     file.__class__ = new_cls
 

diffoscope/profiling.py

@@ -22,6 +22,8 @@ import time
 import contextlib
 import collections
 
+from .utils import format_class
+
 _ENABLED = False
 
 
@@ -53,9 +55,7 @@ class ProfileManager:
 
     def increment(self, start, namespace, key):
         if not isinstance(key, str):
-            key = "{}.{}".format(
-                key.__class__.__module__, key.__class__.__name__
-            )
+            key = format_class(key.__class__)
 
         self.data[namespace][key]["time"] += time.time() - start
         self.data[namespace][key]["count"] += 1

diffoscope/utils.py

@@ -63,3 +63,12 @@ def bail_if_non_existing(*paths):
                     "%s: %s: No such file or directory\n" % (sys.argv[0], path)
                 )
         sys.exit(2)
+
+
+def format_class(klass, strip=""):
+    val = "{}.{}".format(klass.__module__, klass.__name__)
+
+    if val.startswith(strip):
+        val = val[len(strip) :]
+
+    return val