I see a warning for this section of code because isfile() is called
with two arguments. It looks like the correct way to write this is to
joinpath() the two arguments, since that is what is done in
self.assistant.super_update() when not self.config['dryrun'].

diff --git a/pygnulib/GLImport.py b/pygnulib/GLImport.py
index d44ceedcec..098bbc59ac 100644
--- a/pygnulib/GLImport.py
+++ b/pygnulib/GLImport.py
@@ -1230,7 +1230,7 @@ AC_DEFUN([%s_FILE_LIST], [\n''' % macro_prefix
                     os.remove(tmpfile)
             else:  # if not self.config['dryrun']
                 backupname = '%s~' % basename
-                if isfile(destdir, basename):
+                if isfile(joinpath(destdir, basename)):
                     print('Update %s (backup in %s)' % (basename, backupname))
                 else:  # if not isfile(destdir, basename)
                     print('Create %s' % basename)

Collin