Revert replacing % with .format

rsa/cli.py

@@ -178,7 +178,7 @@ def parse_cli(self) -> typing.Tuple[optparse.Values, typing.List[str]]:
     def read_key(self, filename: str, keyform: str) -> rsa.key.AbstractKey:
         """Reads a public or private key."""
 
-        print("Reading {} key from {}".format(self.keyname, filename), file=sys.stderr)
+        print("Reading %s key from %s" % (self.keyname, filename), file=sys.stderr)
         with open(filename, "rb") as keyfile:
             keydata = keyfile.read()
 

rsa/key.py

@@ -140,7 +140,7 @@ def _assert_format_exists(
         except KeyError as ex:
             formats = ", ".join(sorted(methods.keys()))
             raise ValueError(
-                "Unsupported format: {!r}, try one of {}".format(file_format, formats)
+                "Unsupported format: %r, try one of %s" % (file_format, formats)
             ) from ex
 
     def save_pkcs1(self, format: str = "PEM") -> bytes:

rsa/util.py

@@ -67,7 +67,7 @@ def private_to_public() -> None:
     # Read the input data
     if cli.infilename:
         print(
-            "Reading private key from {} in {} format".format(cli.infilename, cli.inform),
+            "Reading private key from %s in %s format" % (cli.infilename, cli.inform),
             file=sys.stderr,
         )
         with open(cli.infilename, "rb") as infile:
@@ -87,7 +87,7 @@ def private_to_public() -> None:
 
     if cli.outfilename:
         print(
-            "Writing public key to {} in {} format".format(cli.outfilename, cli.outform),
+            "Writing public key to %s in %s format" % (cli.outfilename, cli.outform),
             file=sys.stderr,
         )
         with open(cli.outfilename, "wb") as outfile: