# -*- coding: utf-8 -*-
import os
from sceptre.resolvers import Resolver
[docs]class EnvironmentVariable(Resolver):
"""
Resolver for shell environment variables.
:param argument: Name of the environment variable to return.
:type argument: str
"""
def __init__(self, *args, **kwargs):
super(EnvironmentVariable, self).__init__(*args, **kwargs)
[docs] def resolve(self):
"""
Retrieves the value of a named environment variable.
:returns: Value of the environment variable.
:rtype: str
"""
value = None
if self.argument:
value = os.environ.get(self.argument)
return value