Replace toml with tomli (#829)

* Replace `toml` with `tomli`

* Only require `tomli` on Python < 3.11

* Update test-requirements.txt

Co-authored-by: Eric Brown <ericwb@users.noreply.github.com>

bandit/core/config.py

@@ -3,13 +3,17 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 import logging
+import sys
 
 import yaml
 
-try:
-    import toml
-except ImportError:
-    toml = None
+if sys.version_info >= (3, 11):
+    import tomllib
+else:
+    try:
+        import tomli as tomllib
+    except ImportError:
+        tomllib = None
 
 from bandit.core import constants
 from bandit.core import extension_loader
@@ -34,23 +38,23 @@ def __init__(self, config_file=None):
 
         if config_file:
             try:
-                f = open(config_file)
+                f = open(config_file, "rb")
             except OSError:
                 raise utils.ConfigError(
                     "Could not read config file.", config_file
                 )
 
             if config_file.endswith(".toml"):
-                if toml is None:
+                if tomllib is None:
                     raise utils.ConfigError(
                         "toml parser not available, reinstall with toml extra",
                         config_file,
                     )
 
                 try:
                     with f:
-                        self._config = toml.load(f)["tool"]["bandit"]
-                except toml.TomlDecodeError as err:
+                        self._config = tomllib.load(f)["tool"]["bandit"]
+                except tomllib.TOMLDecodeError as err:
                     LOG.error(err)
                     raise utils.ConfigError("Error parsing file.", config_file)
             else:

setup.cfg

@@ -31,7 +31,7 @@ project_urls =
 yaml =
     PyYAML
 toml =
-    toml
+    tomli>=1.1.0; python_version < "3.11"
 
 [entry_points]
 console_scripts =

test-requirements.txt

@@ -7,6 +7,6 @@ flake8>=4.0.0 # Apache-2.0
 stestr>=2.5.0 # Apache-2.0
 testscenarios>=0.5.0 # Apache-2.0/BSD
 testtools>=2.3.0 # MIT
-toml # MIT
+tomli>=1.1.0;python_version<"3.11" # MIT
 beautifulsoup4>=4.8.0 # MIT
 pylint==1.9.4 # GPLv2