remove also a bunch of %-format

IPython/core/application.py

@@ -310,7 +310,7 b' class BaseIPythonApplication(Application):'
                 except OSError as e:
                     # this will not be EEXIST
                     self.log.error("couldn't create path %s: %s", path, e)
-            self.log.debug("IPYTHONDIR set to: %s" % new)
+            self.log.debug("IPYTHONDIR set to: %s", new)
 
     def load_config_file(self, suppress_errors=IPYTHON_SUPPRESS_CONFIG_ERRORS):
         """Load the config file.
@@ -467,7 +467,7 b' class BaseIPythonApplication(Application):'
         s = self.generate_config_file()
         config_file = Path(self.profile_dir.location) / self.config_file_name
         if self.overwrite or not config_file.exists():
-            self.log.warning("Generating default config file: %r" % (config_file))
+            self.log.warning("Generating default config file: %r", (config_file))
             config_file.write_text(s, encoding="utf-8")
 
     @catch_config_error

IPython/core/shellapp.py

@@ -278,7 +278,7 b' class InteractiveShellApp(Configurable):'
             )
             for ext in extensions:
                 try:
-                    self.log.info("Loading IPython extension: %s" % ext)
+                    self.log.info("Loading IPython extension: %s", ext)
                     self.shell.extension_manager.load_extension(ext)
                 except:
                     if self.reraise_ipython_extension_failures: