use get_distribution from pkg_resources instead of mucking about in src dir

Author: rstevens011

.gitignore

@@ -18,4 +18,4 @@ dist/
 .tox/
 venv/
 env/
-src/aws_secretsmanager_caching/version.py
+

setup.py

@@ -21,9 +21,7 @@
         'Programming Language :: Python :: 3.7'
     ],
     keywords='secretsmanager secrets manager development cache caching client',
-    use_scm_version={
-        'write_to': 'src/aws_secretsmanager_caching/version.py'
-    },
+    use_scm_version=True,
     python_requires='>3.5',
     install_requires=['botocore'],
     setup_requires=['pytest-runner', 'setuptools-scm'],

src/aws_secretsmanager_caching/secret_cache.py

@@ -14,6 +14,7 @@
 from copy import deepcopy
 
 import botocore.session
+from pkg_resources import DistributionNotFound, get_distribution
 
 from .cache import LRUCache, SecretCacheItem
 from .config import SecretCacheConfig
@@ -22,6 +23,11 @@
 class SecretCache:
     """Secret Cache client for AWS Secrets Manager secrets"""
 
+    try:
+        __version__ = get_distribution(__name__).version
+    except DistributionNotFound:
+        __version__ = '0.0.0'
+
     def __init__(self, config=SecretCacheConfig(), client=None):
         """Construct a secret cache using the given configuration and
         AWS Secrets Manager boto client.
@@ -38,13 +44,7 @@ def __init__(self, config=SecretCacheConfig(), client=None):
         if self._client is None:
             self._client = botocore.session.get_session().create_client("secretsmanager")
 
-        try:
-            from .version import version
-        except ModuleNotFoundError:
-            version = '0.0.0'
-
-        self._version = version
-        self._client.meta.config.user_agent_extra = "AwsSecretCache/{}".format(self._version)
+        self._client.meta.config.user_agent_extra = "AwsSecretCache/{}".format(SecretCache.__version__)
 
     def _get_cached_secret(self, secret_id):
         """Get a cached secret for the given secret identifier.