Merge pull request #166 from martimunicoy/logger_improvements

Add handler managers to logger

examples/alchemistry/ethylene_to_chlorofom.ipynb

@@ -467,7 +467,7 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3",
+   "display_name": "Python 3 (ipykernel)",
    "language": "python",
    "name": "python3"
   },
@@ -481,9 +481,9 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.7.10"
+   "version": "3.8.12"
   }
  },
  "nbformat": 4,
  "nbformat_minor": 5
-}
+}

peleffy/tests/test_utils.py

@@ -191,6 +191,61 @@ def test_get_logger_level(self):
         level = logger.get_level()
         assert level == 'CRITICAL', 'Unexpected Logger level'
 
+    def test_stdout_handler(self):
+        """
+        It tests the stdout handler of peleffy's logger.
+        """
+        import io
+        import logging
+        from contextlib import redirect_stdout
+        from peleffy.utils import Logger
+
+        # Force a hard reset of logging library and the logger it manages
+        from importlib import reload
+        logging.shutdown()
+        reload(logging)
+
+        logger = Logger()
+
+        with io.StringIO() as buf:
+            with redirect_stdout(buf):
+                logger.set_stdout_handler()
+
+                logger.debug('This message must not be printed')
+                logger.info('This message must be printed')
+
+            output = buf.getvalue()
+
+        assert output.strip() == 'This message must be printed', \
+            'Unexpected logger message'
+
+    def test_file_handler(self):
+        """
+        It tests the file handler of peleffy's logger.
+        """
+        import logging
+        from peleffy.utils import Logger
+        from peleffy.utils import temporary_cd
+
+        # Force a hard reset of logging library and the logger it manages
+        from importlib import reload
+        logging.shutdown()
+        reload(logging)
+
+        logger = Logger()
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            with temporary_cd(tmpdir):
+                logger.set_file_handler('log.txt')
+
+                logger.debug('This message must not be printed')
+                logger.info('This message must be printed')
+
+                with open('log.txt') as f:
+                    output = '\n'.join(f.readlines())
+
+                assert output.strip() == 'This message must be printed', \
+                    'Unexpected logger message'
 
 class TestOutputPathHandler(object):
     """

peleffy/utils/utils.py

@@ -411,16 +411,74 @@ def __init__(self):
         if 'peleffy_log' not in logging.root.manager.loggerDict:
             self._logger = logging.getLogger('peleffy_log')
             self._logger.setLevel(self.DEFAULT_LEVEL)
+
+            # Add stream handler
+            self.set_stdout_handler()
         else:
             self._logger = logging.getLogger('peleffy_log')
 
-        # If no handler is found add stream handler
-        if not len(self._logger.handlers):
-            ch = logging.StreamHandler()
-            ch.setLevel(self.DEFAULT_LEVEL)
-            formatter = logging.Formatter('%(message)s')
-            ch.setFormatter(formatter)
-            self._logger.addHandler(ch)
+    def set_stdout_handler(self):
+        """
+        It unsets current Logger's handlers and sets the stream handler
+        that points to the standard output.
+        """
+        import sys
+        import logging
+
+        # Unset current file handlers
+        self._unset_handlers()
+
+        # Initialize stream handler
+        stream_handler = logging.StreamHandler(sys.stdout)
+
+        # Assign logger's level
+        level = self.get_level()
+        stream_handler.setLevel(level)
+
+        # Set up logger's format
+        stream_handler.setFormatter(logging.Formatter('%(message)s'))
+
+        # Add handler
+        self._logger.addHandler(stream_handler)
+
+    def set_file_handler(self, log_file):
+        """
+        It unsets current Logger's handlers and sets the file handler
+        that points to the supplied path.
+
+        Parameters
+        ----------
+        log_file : str
+            Path where to save logger's output
+        """
+        import os
+        import logging
+
+        # Unset current file handlers
+        self._unset_handlers()
+
+        # Initialize file handler
+        if not os.path.isfile(log_file):
+            file_handler = logging.FileHandler(log_file, mode="w+")
+        else:
+            file_handler = logging.FileHandler(log_file, mode="a")
+
+        # Assign logger's level
+        level = self.get_level()
+        file_handler.setLevel(level)
+
+        # Set up logger's format
+        file_handler.setFormatter(logging.Formatter('%(message)s'))
+
+        # Add handler
+        self._logger.addHandler(file_handler)
+
+    def _unset_handlers(self):
+        """
+        It removes any handler of this Logger.
+        """
+        for handler in self._logger.handlers:
+            self._logger.removeHandler(handler)
 
     def set_level(self, level):
         """
@@ -433,6 +491,7 @@ def set_level(self, level):
             CRITICAL]
         """
         import logging
+        logging.basicConfig()
 
         if level.upper() == 'DEBUG':
             logging_level = logging.DEBUG