kwutil.util_environ module

Quickly test the truthiness of an environment variable.

kwutil.util_environ.envflag(key, default=None, environ=None)[source]

Determine if an environment variable is specified and truthy or falsy.

Parameters:

  • key (str) – the environment variable name to check

  • default (Any) – the default value to return if the environment variable is not specified.

  • environ (None | Dict) – Uses this to get the environment variable. If unspecified, defaults to os.environ.

Returns:

True if the environment variable exist and matches a truthy pattern. (e.g. true, on, yes, 1, or t). Otherwise returns False.

Note

This will return false on any setting of the environ that is not truthy. (e.g. YESPLEASE is not a registered TRUTHY_ENVIRON so it will return False).

Example

>>> from kwutil import util_environ
>>> environ = {
>>>     'foo': '1',
>>>     'bar': 'YES',
>>>     'baz': '0',
>>>     'biz': '1111',
>>> }
>>> assert util_environ.envflag('foo', 0, environ=environ)
>>> assert util_environ.envflag('bar', 0, environ=environ)
>>> assert not util_environ.envflag('baz', 0, environ=environ)
>>> assert not util_environ.envflag('biz', 0, environ=environ)
>>> assert not util_environ.envflag('buzz', 0, environ=environ)
>>> assert util_environ.envflag('buzz', 1, environ=environ)