# Licensed under a 3-clause BSD style license - see LICENSE.rst
"""Utils to create scripts and command-line tools"""
import sys
import logging
import yaml
from os.path import expandvars
from pathlib import Path
__all__ = ["read_yaml", "write_yaml", "make_path", "recursive_merge_dicts"]
def _configure_root_logger(level="info", format=None):
"""Configure root log level and format.
This is a helper function that can be called form
"""
log = logging.getLogger() # Get root logger
# Set log level
# level = getattr(logging, level.upper())
numeric_level = getattr(logging, level.upper(), None)
if not isinstance(numeric_level, int):
raise ValueError("Invalid log level: {}".format(level))
log.setLevel(level=numeric_level)
# Format log handler
if not format:
# format = '%(asctime)s %(name)-12s %(levelname)-8s %(message)s'
format = "%(levelname)-8s %(message)s [%(name)s]"
formatter = logging.Formatter(format)
# Not sure why there sometimes is a handler attached to the root logger,
# and sometimes not, i.e. why this is needed:
# https://github.com/gammapy/gammapy/pull/318/files#r36453321
if len(log.handlers) == 0:
handler = logging.StreamHandler(sys.stderr)
handler.setLevel(numeric_level)
log.addHandler(handler)
log.handlers[0].setFormatter(formatter)
return log
[docs]def read_yaml(filename, logger=None):
"""
Read YAML file
Parameters
----------
filename : `pathlib.Path`, str
File to read
"""
filename = make_path(filename)
if logger is not None:
logger.info("Reading {}".format(filename))
with open(str(filename)) as fh:
dictionary = yaml.safe_load(fh)
return dictionary
[docs]def write_yaml(dictionary, filename, logger=None):
"""Write YAML file.
Parameters
----------
dictionary : dict
Python dictionary
filename : str, `~gammapy.exter.pathlib.Path`
file to write
"""
filename = make_path(filename)
filename.parent.mkdir(exist_ok=True)
if logger is not None:
logger.info("Writing {}".format(filename))
with open(str(filename), "w") as outfile:
outfile.write(yaml.safe_dump(dictionary, default_flow_style=False))
[docs]def make_path(path):
"""Expand environment variables on `~pathlib.Path` construction.
Parameters
----------
path : str, `pathlib.Path`
path to expand
"""
# TODO: raise error or warning if environment variables that don't resolve are used
# e.g. "spam/$DAMN/ham" where `$DAMN` is not defined
# Otherwise this can result in cryptic errors later on
return Path(expandvars(str(path)))
[docs]def recursive_merge_dicts(a, b):
"""Recursively merge two dictionaries.
Entries in b override entries in a. The built-in update function cannot be
used for hierarchical dicts, see:
http://stackoverflow.com/questions/3232943/update-value-of-a-nested-dictionary-of-varying-depth/3233356#3233356
Parameters
----------
a : dict
dictionary to be merged
b : dict
dictionary to be merged
Returns
-------
c : dict
merged dict
Examples
--------
>>> from gammapy.utils.scripts import recursive_merge_dicts
>>> a = dict(a=42, b=dict(c=43, e=44))
>>> b = dict(d=99, b=dict(c=50, g=98))
>>> c = recursive_merge_dicts(a, b)
>>> print(c)
{'a': 42, 'b': {'c': 50, 'e': 44, 'g': 98}, 'd': 99}
"""
c = a.copy()
for k, v in b.items():
if k in c and isinstance(c[k], dict):
c[k] = recursive_merge_dicts(c[k], v)
else:
c[k] = v
return c