Source code for gammapy.utils.scripts

# Licensed under a 3-clause BSD style license - see LICENSE.rst
"""Utils to create scripts and command-line tools"""
from __future__ import absolute_import, division, print_function, unicode_literals
import sys
import logging
from os.path import expandvars
from ..extern.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))

    # 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:
    if len(log.handlers) == 0:
        handler = logging.StreamHandler(sys.stderr)


    return log

[docs]def read_yaml(filename, logger=None): """ Read YAML file Parameters ---------- filename : `~gammapy.extern.pathlib.Path`, str File to read """ import yaml filename = make_path(filename) if logger is not None:"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 """ import yaml filename = make_path(filename) filename.parent.mkdir(exist_ok=True) if logger is not None:"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, `~gammapy.extern.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: 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