config: split console logging between stdout & stderr base on level

mylib/config.py

@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+# pylint: disable=too-many-lines
 
 """ Configuration & options parser """
 
@@ -136,14 +137,17 @@ class BaseOption:  # pylint: disable=too-many-instance-attributes
     @property
     def parser_dest(self):
         """ Get option name in arguments parser options """
-        return '{0}_{1}'.format(self.section.name, self.name)
+        return f'{self.section.name}_{self.name}'
 
     @property
     def parser_help(self):
         """ Get option help message in arguments parser options """
         if self.arg_help and self.default is not None:
+            # pylint: disable=consider-using-f-string
             return '{0} (Default: {1})'.format(
-                self.arg_help, re.sub(r'%([^%])', r'%%\1', str(self.default)))
+                self.arg_help,
+                re.sub(r'%([^%])', r'%%\1', str(self._default_in_config))
+            )
         if self.arg_help:
             return self.arg_help
         return None
@@ -153,9 +157,7 @@ class BaseOption:  # pylint: disable=too-many-instance-attributes
         """ Get option argument name in parser options """
         return (
             self.arg if self.arg else
-            '--{0}-{1}'.format(
-                self.section.name, self.name
-            ).lower().replace('_', '-')
+            f'--{self.section.name}-{self.name}'.lower().replace('_', '-')
         )
 
     def add_option_to_parser(self, section_opts):
@@ -292,6 +294,7 @@ class BooleanOption(BaseOption):
     @property
     def parser_argument_name(self):
         """ Get option argument name in parser options """
+        # pylint: disable=consider-using-f-string
         return (
             self.arg if self.arg else
             '--{0}-{1}-{2}'.format(
@@ -304,7 +307,7 @@ class BooleanOption(BaseOption):
     def _ask_value(self, prompt=None, **kwargs):
         """ Ask to user to enter value of this option and return it """
         default_value = self.get()
-        prompt = "%s: " % self.name
+        prompt = f'{self.name}: '
         if default_value:
             prompt += '[Y/n] '
         else:
@@ -413,12 +416,11 @@ class PasswordOption(StringOption):
         value = keyring.get_password(service_name, username)
 
         if value is None:
+            # pylint: disable=consider-using-f-string
             value = getpass(
-                'Please enter %s%s: ' % (
-                    self.comment if self.comment else
-                    '%s %s' % (self.section.name, self.name),
-                    (' for %s' % username)
-                    if username != self.name else ''
+                'Please enter {0}{1}: '.format(
+                    f'{self.section.name} {self.name}',
+                    f' for {username}' if username != self.name else ''
                 )
             )
             keyring.set_password(service_name, username, value)
@@ -445,11 +447,11 @@ class PasswordOption(StringOption):
             print('# ' + self.comment)
         default_value = kwargs.pop('default_value', self.get())
         if not prompt:
-            prompt = '%s: ' % self.name
+            prompt = f'{self.name}: '
             if default_value is not None:
                 # Hide value only if it differed from default value
                 if default_value == self.default:
-                    prompt += '[%s] ' % default_value
+                    prompt += f'[{default_value}] '
                 else:
                     prompt += '[secret defined, leave to empty to keep it as unchange] '
         value = getpass(prompt)
@@ -466,8 +468,8 @@ class PasswordOption(StringOption):
             default_use_keyring = (super().get() == self.keyring_value)
             while use_keyring is None:
                 prompt = (
-                    'Do you want to use XDG keyring ? [%s] ' %
-                    ('Y/n' if default_use_keyring else 'y/N')
+                    'Do you want to use XDG keyring ? '
+                    f"[{'Y/n' if default_use_keyring else 'y/N'}] "
                 )
                 result = input(prompt).lower()
                 if result == '':
@@ -488,7 +490,7 @@ class ConfigSection:
     def __init__(self, config, name, comment=None, order=None):
         self.config = config
         self.name = name
-        self.options = dict()
+        self.options = {}
         self.comment = comment
         self.order = order if isinstance(order, int) else 10
 
@@ -500,7 +502,7 @@ class ConfigSection:
         :param name: Option name
         :param **kwargs: Dict of raw option for type class
         """
-        assert not self.defined(name), "Duplicated option %s" % name
+        assert not self.defined(name), f'Duplicated option {name}'
         self.options[name] = _type(self.config, self, name, **kwargs)
         return self.options[name]
 
@@ -514,12 +516,12 @@ class ConfigSection:
 
     def get(self, option):
         """ Get option value """
-        assert self.defined(option), "Option %s unknown" % option
+        assert self.defined(option), f'Option {option} unknown'
         return self.options[option].get()
 
     def set(self, option, value):
         """ Set option value """
-        assert self.defined(option), "Option %s unknown" % option
+        assert self.defined(option), f'Option {option} unknown'
         return self.options[option].set(value)
 
     def add_options_to_parser(self, parser):
@@ -530,16 +532,16 @@ class ConfigSection:
             else self.name.capitalize()
         )
 
-        for option in self.options:
+        for option in self.options:  # pylint: disable=consider-using-dict-items
             self.options[option].add_option_to_parser(section_opts)
 
     def export_to_config(self):
         """ Export section and their options to configuration file """
         lines = []
         if self.comment:
-            lines.append('# %s' % self.comment)
-        lines.append('[%s]' % self.name)
-        for option in self.options:
+            lines.append(f'# {self.comment}')
+        lines.append(f'[{self.name}]')
+        for option in self.options:  # pylint: disable=consider-using-dict-items
             lines.append(self.options[option].export_to_config())
         return '\n'.join(lines)
 
@@ -555,9 +557,9 @@ class ConfigSection:
         :rtype: bool of dict
         """
         if self.comment:
-            print('# %s' % self.comment)
-        print('[%s]\n' % self.name)
-        result = dict()
+            print(f'# {self.comment}')
+        print(f'[{self.name}]''\n')
+        result = {}
         error = False
         for name, option in self.options.items():
             option_result = option.ask_value(set_it=set_it)
@@ -622,7 +624,7 @@ class Config:  # pylint: disable=too-many-instance-attributes
                                 The specified callback method will receive Config object as parameter.
         : param ** kwargs: Raw parameters dict pass to ConfigSection __init__() method
         """
-        assert name not in self.sections, "Duplicated section %s" % name
+        assert name not in self.sections, f'Duplicated section {name}'
 
         self.sections[name] = ConfigSection(self, name, **kwargs)
         if loaded_callback:
@@ -644,7 +646,7 @@ class Config:  # pylint: disable=too-many-instance-attributes
         """ Get option value """
         assert self.config_parser or self.options, 'Unconfigured options parser'
         assert self.defined(
-            section, option), 'Unknown option %s.%s' % (section, option)
+            section, option), f'Unknown option {section}.{option}'
         value = self.sections[section].get(option)
         log.debug('get(%s, %s): %s (%s)', section, option, value, type(value))
         return value
@@ -664,7 +666,7 @@ class Config:  # pylint: disable=too-many-instance-attributes
         """ Set option value """
         assert self.config_parser, 'Unconfigured options parser'
         assert self.defined(
-            section, option), 'Unknown option %s.%s' % (section, option)
+            section, option), f'Unknown option {section}.{option}'
         self.sections[section].set(option, value)
 
     def load_file(self, filepath, execute_callback=True):
@@ -734,7 +736,11 @@ class Config:  # pylint: disable=too-many-instance-attributes
                 'Configuration directory "%s" does not exist (or not writable)', dirpath)
             return False
 
-        lines = ['#\n# %s configuration\n#\n' % self.appname]
+        lines = [
+            '#\n'
+            f'# {self.appname} configuration'
+            '\n#\n'
+        ]
 
         for section_name in self._ordered_section_names:
             lines.append('')
@@ -769,9 +775,15 @@ class Config:  # pylint: disable=too-many-instance-attributes
             formatter_class=RawWrappedTextHelpFormatter,
             **kwargs)
 
-        config_file_help = 'Configuration file to use (default: %s)' % self.config_filepath
+        config_file_help = (
+            f'Configuration file to use (default: {self.config_filepath})'
+        )
         if self.config_file_env_variable:
-            config_file_help += '\n\nYou also could set %s environment variable to specify your configuration file path.' % self.config_file_env_variable
+            config_file_help += (
+                '\n\nYou also could set '
+                f'{self.config_file_env_variable} environment variable to '
+                'specify your configuration file path.'
+            )
         self.options_parser.add_argument(
             '-c',
             '--config',
@@ -854,7 +866,7 @@ class Config:  # pylint: disable=too-many-instance-attributes
             # Load configuration file
             if os.path.isfile(options.config) and not self.load_file(options.config, execute_callback=False):
                 parser.error(
-                    'Failed to load configuration from file %s' % options.config
+                    f'Failed to load configuration from file {options.config}'
                 )
 
             if options.save and not already_saved:
@@ -867,11 +879,20 @@ class Config:  # pylint: disable=too-many-instance-attributes
             logging.getLogger().setLevel(logging.INFO)
 
         if self.get('console', 'enabled'):
-            console_handler = logging.StreamHandler(sys.stdout)
+            stdout_console_handler = logging.StreamHandler(sys.stdout)
+            stdout_console_handler.addFilter(StdoutInfoFilter())
+            stdout_console_handler.setLevel(logging.DEBUG)
+
+            stderr_console_handler = logging.StreamHandler(sys.stderr)
+            stderr_console_handler.setLevel(logging.WARNING)
+
             if self.get('console', 'log_format'):
                 console_formater = logging.Formatter(self.get('console', 'log_format'))
-                console_handler.setFormatter(console_formater)
-            logging.getLogger().addHandler(console_handler)
+                stdout_console_handler.setFormatter(console_formater)
+                stderr_console_handler.setFormatter(console_formater)
+
+            logging.getLogger().addHandler(stdout_console_handler)
+            logging.getLogger().addHandler(stderr_console_handler)
 
         if execute_callback:
             self._loaded()
@@ -907,7 +928,7 @@ class Config:  # pylint: disable=too-many-instance-attributes
         # On set it mode, ensure configuration file parser is initialized
         if set_it and not self.config_parser:
             self.config_parser = ConfigParser()
-        result = dict()
+        result = {}
         error = False
         for name, section in self.sections.items():
             section_result = section.ask_values(set_it=set_it)
@@ -960,14 +981,14 @@ class Config:  # pylint: disable=too-many-instance-attributes
             argv, create=False, execute_callback=False)
 
         if os.path.exists(options.config) and not options.overwrite:
-            print('Configuration file %s already exists' % options.config)
+            print(f'Configuration file {options.config} already exists')
             sys.exit(1)
 
         if options.interactive:
             self.ask_values(set_it=True)
 
         if self.save(options.config):
-            print('Configuration file %s created.' % options.config)
+            print(f'Configuration file {options.config} created.')
             if options.validate:
                 print('Validate your configuration...')
                 try:
@@ -976,14 +997,15 @@ class Config:  # pylint: disable=too-many-instance-attributes
                     else:
                         print('Error(s) occurred validating your configuration. See logs for details.')
                         sys.exit(1)
-                except Exception:
+                except Exception:  # pylint: disable=broad-except
                     print(
-                        'Exception occurred validating your configuration: %s\n\nSee logs for details.' %
-                        traceback.format_exc())
+                        'Exception occurred validating your configuration:\n'
+                        f'{traceback.format_exc()}'
+                        '\n\nSee logs for details.'
+                    )
                     sys.exit(2)
         else:
-            print('Error occured creating configuration file %s' %
-                  options.config)
+            print(f'Error occured creating configuration file {options.config}')
             sys.exit(1)
 
         sys.exit(0)
@@ -1006,8 +1028,8 @@ class Config:  # pylint: disable=too-many-instance-attributes
             return os.environ.get(self.config_file_env_variable)
         return os.path.join(
             self.config_dir,
-            ("%s.ini" % self.shortname) if self.shortname
-            else "config.ini"
+            f'{self.shortname}.ini' if self.shortname
+            else 'config.ini'
         )
 
 
@@ -1044,7 +1066,7 @@ class ConfigurableObject:
                  **kwargs):
 
         for key, value in kwargs.items():
-            assert key in self._defaults, "Unknown %s option" % key
+            assert key in self._defaults, f'Unknown {key} option'
             self._kwargs[key] = value
 
         if options:
@@ -1054,7 +1076,7 @@ class ConfigurableObject:
             elif self._config_name:
                 self._options_prefix = self._config_name + '_'
             else:
-                raise Exception('No configuration name defined for %s' % __name__)
+                raise Exception(f'No configuration name defined for {__name__}')
 
         if config:
             self._config = config
@@ -1063,7 +1085,7 @@ class ConfigurableObject:
             elif self._config_name:
                 self._config_section = self._config_name
             else:
-                raise Exception('No configuration name defined for %s' % __name__)
+                raise Exception(f'No configuration name defined for {__name__}')
 
     def _get_option(self, option, default=None, required=False):
         """ Retreive option value """
@@ -1076,7 +1098,7 @@ class ConfigurableObject:
         if self._config and self._config.defined(self._config_section, option):
             return self._config.get(self._config_section, option)
 
-        assert not required, "Options %s not defined" % option
+        assert not required, f'Options {option} not defined'
 
         return default if default is not None else self._defaults.get(option)
 
@@ -1114,3 +1136,10 @@ class ConfigSectionAsDictWrapper:
 
     def __delitem__(self, key):
         raise Exception('Deleting a configuration option is not supported')
+
+
+# pylint: disable=too-few-public-methods
+class StdoutInfoFilter(logging.Filter):
+    """ Logging filter to keep messages only >= logging.INFO """
+    def filter(self, record):
+        return record.levelno in (logging.DEBUG, logging.INFO)

tests/test_config.py

@@ -1,10 +1,12 @@
 # pylint: disable=redefined-outer-name,missing-function-docstring,protected-access,global-statement
 """ Tests on config lib """
 
+import logging
+
 from mylib.config import Config, ConfigSection
 from mylib.config import StringOption
 
-runned = dict()
+runned = {}
 
 
 def test_config_init_default_args():
@@ -208,3 +210,17 @@ def test_get_default():
     config.parse_arguments_options(argv=[], create=False)
 
     assert config.get(section_name, opt_name) == opt_default_value
+
+
+def test_logging_splited_stdout_stderr(capsys):
+    config = Config('Test app')
+    config.parse_arguments_options(argv=['-C', '-v'], create=False)
+    info_msg = "[info]"
+    err_msg = "[error]"
+    logging.getLogger().info(info_msg)
+    logging.getLogger().error(err_msg)
+    captured = capsys.readouterr()
+    assert info_msg in captured.out
+    assert info_msg not in captured.err
+    assert err_msg in captured.err
+    assert err_msg not in captured.out