"""Dot environment files helper module."""
import re
from os import environ, sys
from pathlib import Path
from .logger import logger
log_env, debug_env = logger('VarEnv')
[docs]def getenv(key: str,
default: str = None,
max_parents: int = None,
dotenv: str = '.env') -> str:
"""Get environnement variables from dotenv file or globally.
Parameters
----------
key: str
Key to query on the environment
default: str, optional
Optional value if not found.
max_parents: int, optional
Max number of parent to check recursively for a ``.env`` file.
To search only the current parent set ``max_parents=0``.
Default: ``None``.
dotenv: str, optional
Dotenv file to search (default: ``'.env'``).
To load only the global variables set ``dotenv=None``.
Returns
-------
str
Environment variable value. None, if not found.
Note
----
The function first search for a ``.env`` file in the
current working directory, then in its parents up to
the root. If a ``.env`` file is found, the search is
stopped and the file is parsed for key-values.
If not present, the function will search globally if
the value is present.
"""
if dotenv and (env := find_dotenv(max_parents=max_parents, fname=dotenv)):
data = parse_dotenv(env)
if key in data:
value = data[key]
log_env.info('Search for `%s`. Found value: `%s` (in %s)', key, value, env)
return value
if key in environ:
value = environ.get(key)
log_env.info('Search for `%s`. Found value: `%s` (globally)', key, value)
return value
log_env.info('Search for `%s`. Not found, use default: `%s`', key, default)
return default
[docs]def find_dotenv(max_parents: int = None, fname: str = '.env') -> Path:
"""Search for .env file in the working directory and its parents.
Parameters
----------
max_parents: int, optional
Max number of parent to check recursively for a ``.env`` file.
To search only the current parent set ``max_parents=0``.
Default: ``None``.
fname: str, optional
Dotenv file to search (default: ``'.env'``).
Returns
-------
pathlib.Path or None
File path object.
Note
----
Only the first parent with a ``.env`` if returned.
"""
cwd = Path().resolve()
for parent in [cwd, *list(cwd.parents)[:max_parents]]:
if (env := parent / fname).exists():
log_env.debug('%s found', env)
return env
return None
KEY = re.compile(r'[a-zA-Z_]+[a-zA-Z0-9_]*')
KEY_VALUE = re.compile(rf'^({KEY.pattern})\s*=\s*(.*)')
INTERP = re.compile(rf'\${{({KEY.pattern})}}')
def parse_dotenv(dot_file: str) -> dict:
"""Read dotenv file.
Parameters
----------
fname: str or pathlib.Path
Dot environment file to parse.
Returns
-------
dict
Parsed environment file as a dict.
"""
fname = Path(dot_file)
data, values = {}, []
for line in fname.read_text(encoding='utf-8').splitlines():
if values:
if line.endswith('"""') or line.endswith("'''"):
key = values[0]
value = '\n'.join(values[1:] + [line[:-3]])
data[key] = env_interpolation(value, data, skip=line.endswith("'"))
values = []
else:
values.append(line)
continue
line = line.strip()
if not line or line.startswith('#'):
continue
if match := KEY_VALUE.findall(line):
key, value = match[0]
# Start multi-lines
if value.startswith('"""') or value.startswith("'''"):
values = [key, value[3:]]
continue
# Remove single/double quotes
if is_quoted(value):
value = value[1:-1]
# Remove comment (in not quoted strings only)
elif '#' in value:
value, _ = value.split('#', 1)
value = value.strip()
data[key] = env_interpolation(value, data, skip=line.endswith("'"))
return data
def is_quoted(string: str) -> bool:
"""Check if the string is quoted (single or double)."""
if string.startswith("'") and string.endswith("'"):
return True
if string.startswith('"') and string.endswith('"'):
return True
return False
def env_interpolation(string: str, data: dict, skip: bool = False) -> str:
"""Environment variable interpolation."""
if skip or not (matches := INTERP.findall(string)):
return string
for key in matches:
if key in data:
string = string.replace(f'${{{key}}}', data[key])
elif key in environ:
string = string.replace(f'${{{key}}}', environ[key])
return string
[docs]def print_kernels_dir(dotenv: str = '.env') -> None:
"""Print kernels folders defined with ENV variables.
Parameters
----------
dotenv: str, optional
Dotenv file to search (default: ``'.env'``).
To load only the global variables set ``dotenv=None``.
"""
kernels = {
k: (v, '')
for k, v in environ.items()
if k.startswith('KERNELS_')
}
if fname := find_dotenv(fname=dotenv):
sys.stdout.write(f'Dotenv file found:\n- {fname}\n\n')
for k, v in parse_dotenv(fname).items():
if k.startswith('KERNELS_'):
kernels[k] = (v, ' (.env)')
sys.stdout.write('Kernels ENV variables:\n')
if kernels:
n = max(map(len, kernels))
for mission, (path, loc) in kernels.items():
sys.stdout.write(f'- {mission:{n}s}: {path}{loc}\n')
else:
sys.stdout.write('- None\n')
