From: layday <layday@protonmail.com>
Date: Mon, 3 Feb 2020 14:40:49 +0000 (-0500)
Subject: Move use of ``__file__`` to be local to template access
X-Git-Tag: rel_1_4_0~5
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b3ce609f5d39fa485e39f78dfd3ed6c2b4d9d474;p=thirdparty%2Fsqlalchemy%2Falembic.git

Move use of ``__file__`` to be local to template access

Moved the use of the ``__file__`` attribute at the base of the Alembic
package into the one place that it is specifically needed, which is when
the config attempts to locate the template directory. This helps to allow
Alembic to be fully importable in environments that are using Python
memory-only import schemes.  Pull request courtesy layday.

Partially-fixes: #648
Closes: #651
Pull-request: https://github.com/sqlalchemy/alembic/pull/651
Pull-request-sha: c30299dbc3499c59e81602d91deb3b03166b4583

Change-Id: I2607031d80c418ce4d7e779eeb42c57a53a72ce0
---

diff --git a/alembic/__init__.py b/alembic/__init__.py
index a63c0220..4d4fbaa2 100644
--- a/alembic/__init__.py
+++ b/alembic/__init__.py
@@ -1,4 +1,3 @@
-from os import path
 import sys
 
 from . import context  # noqa
@@ -8,7 +7,5 @@ from .runtime import migration
 
 __version__ = '1.3.4'
 
-package_dir = path.abspath(path.dirname(__file__))
-
 sys.modules["alembic.migration"] = migration
 sys.modules["alembic.environment"] = environment
diff --git a/alembic/config.py b/alembic/config.py
index 48c41cb8..f2c6ef90 100644
--- a/alembic/config.py
+++ b/alembic/config.py
@@ -4,7 +4,6 @@ import os
 import sys
 
 from . import command
-from . import package_dir
 from . import util
 from .util import compat
 from .util.compat import SafeConfigParser
@@ -210,6 +209,9 @@ class Config(object):
         commands.
 
         """
+        import alembic
+
+        package_dir = os.path.abspath(os.path.dirname(alembic.__file__))
         return os.path.join(package_dir, "templates")
 
     def get_section(self, name, default=None):
diff --git a/docs/build/unreleased/648_file.rst b/docs/build/unreleased/648_file.rst
new file mode 100644
index 00000000..12c433e9
--- /dev/null
+++ b/docs/build/unreleased/648_file.rst
@@ -0,0 +1,9 @@
+.. change::
+    :tags: usecase, environment
+    :tickets: 648
+
+    Moved the use of the ``__file__`` attribute at the base of the Alembic
+    package into the one place that it is specifically needed, which is when
+    the config attempts to locate the template directory. This helps to allow
+    Alembic to be fully importable in environments that are using Python
+    memory-only import schemes.  Pull request courtesy layday.