Make core library unopinionated wrt. logging configuration (#184)

docs/usage.rst

@@ -126,26 +126,18 @@ the iteration names and realization indices.
 Obtaining warning and error messages
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-fmu-ensemble will by default be mute to warnings and error messages,
-unless you tell it to be verbose in your client code. The available debug
-levels are `DEBUG`, `INFO`, `WARNING`, `ERROR` and `CRITICAL` where `WARNING`
-is the default.
-
-Script authors can set a different default logging level by inserting
-the lines
+Application/script authors can configure logging output to console by e.g.
 
 .. code-block:: python
 
-    from fmu.ensemble import etc
-    fmux = etc.Interaction()
-    logger = fmux.basiclogger(__name__, level='INFO')
+    import logging
+
+    logging.basicConfig(level=logging.INFO)
 
-while users can always override this by setting an environment variable:
+See documentation on `Python logging`_ for more details.
 
-.. code-block:: console
+.. _Python logging: https://docs.python.org/3/library/logging.html
 
-    export FMU_LOGGING_LEVEL=INFO  # If bash shell
-    setenv FMU_LOGGING_LEVEL INFO  # If c-shell (default shell in equinor)
 
 Reading Eclipse data
 ^^^^^^^^^^^^^^^^^^^^

src/fmu/ensemble/ensemble.py

@@ -4,14 +4,14 @@
 import os
 import glob
 import dateutil
+import logging
 
 import pandas as pd
 import numpy as np
 import yaml
 from ecl import EclDataType
 from ecl.eclfile import EclKW
 
-from .etc import Interaction
 from .realization import ScratchRealization
 from .virtualrealization import VirtualRealization
 from .virtualensemble import VirtualEnsemble
@@ -20,8 +20,7 @@
 from .util import shortcut2path
 from .util.dates import unionize_smry_dates
 
-xfmu = Interaction()
-logger = xfmu.functionlogger(__name__)
+logger = logging.getLogger(__name__)
 
 
 class ScratchEnsemble(object):

src/fmu/ensemble/ensemblecombination.py

@@ -1,13 +1,11 @@
 """Module for handling linear combinations of ensembles"""
 
 import fnmatch
+import logging
 
 import pandas as pd
 
-from .etc import Interaction
-
-xfmu = Interaction()
-logger = xfmu.functionlogger(__name__)
+logger = logging.getLogger(__name__)
 
 
 class EnsembleCombination(object):

src/fmu/ensemble/ensembleset.py

@@ -3,15 +3,14 @@
 import re
 import os
 import glob
+import logging
 
 import numpy as np
 import pandas as pd
 
-from .etc import Interaction
 from .ensemble import ScratchEnsemble, VirtualEnsemble
 
-xfmu = Interaction()
-logger = xfmu.functionlogger(__name__)
+logger = logging.getLogger(__name__)
 
 
 class EnsembleSet(object):