Merge #31420

src/sage/__init__.py

@@ -1,14 +1,7 @@
-__all__ = ['all']
+# Do not add anything to this file.
+# It will be removed soon in order to turn 'sage' into a native namespace package.
+# See https://trac.sagemath.org/ticket/29705
 
-# Set sage.__version__ to the current version number. This is analogous
-# to many other Python packages.
-from sage.version import version as __version__
-
-import sys
-# Make sure that the correct zlib library is loaded. This is needed
-# to prevent the system zlib to be loaded instead of the Sage one.
-# See https://trac.sagemath.org/ticket/23122
-import zlib
 
 # IPython calls this when starting up
 def load_ipython_extension(*args):
@@ -44,51 +37,3 @@ def isfunction(obj):
     deprecation(32479, "sage.isfunction is deprecated; use callable or sage.misc.sageinspect.is_function_or_cython_function instead")
     from sage.misc.sageinspect import is_function_or_cython_function
     return is_function_or_cython_function(obj)
-
-
-# Monkey-patch ExtensionFileLoader to allow IPython to find the sources
-# of Cython files. See https://trac.sagemath.org/ticket/24681
-try:
-    from importlib.machinery import ExtensionFileLoader
-except ImportError:
-    pass  # Python 2
-else:
-    del ExtensionFileLoader.get_source
-
-
-# Work around a Cygwin-specific bug caused by sqlite3; see
-# https://trac.sagemath.org/ticket/30157 and the docstring for
-# fix_for_ticket_30157
-# Here we monkey-patch the sqlite3 module to ensure the fix is
-# applied the very first time a connection is made to a sqlite3
-# database
-if sys.platform == 'cygwin':
-    def patch_sqlite3():
-        try:
-            from sage.misc.sage_ostools import fix_for_ticket_30157
-        except ImportError:
-            # The module might not have been re-built yet; don't worry about it
-            # then
-            return
-
-        import sqlite3
-        import functools
-        orig_sqlite3_connect = sqlite3.connect
-
-        @functools.wraps(orig_sqlite3_connect)
-        def connect(*args, **kwargs):
-            if fix_for_ticket_30157():
-                raise RuntimeError(
-                    'patch for Trac ticket #30157 failed; please report this '
-                    'bug to https://trac.sagemath.org')
-
-            # Undo the monkey-patch
-            try:
-                return orig_sqlite3_connect(*args, **kwargs)
-            finally:
-                sqlite3.connect = orig_sqlite3_connect
-
-        sqlite3.connect = connect
-
-    patch_sqlite3()
-    del patch_sqlite3

src/sage/cpython/__init__.py

@@ -0,0 +1,55 @@
+# sage.cpython is an ordinary package, not a namespace package.
+
+# This package is imported very early, which is why workarounds/monkey-patching
+# are done in this file.
+
+# Make sure that the correct zlib library is loaded. This is needed
+# to prevent the system zlib to be loaded instead of the Sage one.
+# See https://trac.sagemath.org/ticket/23122
+import zlib as _zlib
+del _zlib
+
+# Monkey-patch ExtensionFileLoader to allow IPython to find the sources
+# of Cython files. See https://trac.sagemath.org/ticket/24681
+from importlib.machinery import ExtensionFileLoader as _ExtensionFileLoader
+del _ExtensionFileLoader.get_source
+del _ExtensionFileLoader
+
+# Work around a Cygwin-specific bug caused by sqlite3; see
+# https://trac.sagemath.org/ticket/30157 and the docstring for
+# fix_for_ticket_30157
+# Here we monkey-patch the sqlite3 module to ensure the fix is
+# applied the very first time a connection is made to a sqlite3
+# database
+import sys as _sys
+if _sys.platform == 'cygwin':
+    def _patch_sqlite3():
+        try:
+            from sage.misc.sage_ostools import fix_for_ticket_30157
+        except ImportError:
+            # The module might not have been re-built yet; don't worry about it
+            # then
+            return
+
+        import sqlite3
+        import functools
+        orig_sqlite3_connect = sqlite3.connect
+
+        @functools.wraps(orig_sqlite3_connect)
+        def connect(*args, **kwargs):
+            if fix_for_ticket_30157():
+                raise RuntimeError(
+                    'patch for Trac ticket #30157 failed; please report this '
+                    'bug to https://trac.sagemath.org')
+
+            # Undo the monkey-patch
+            try:
+                return orig_sqlite3_connect(*args, **kwargs)
+            finally:
+                sqlite3.connect = orig_sqlite3_connect
+
+        sqlite3.connect = connect
+
+    _patch_sqlite3()
+    del _patch_sqlite3
+    del _sys