Remove use of SAGE_LIB in sage.misc

[mkoeppe]

We delay importing lazy_import_cache until a lazy star import is done (which the Sage library never does).

We change two copies of essentially the same code that tries to use SAGE_SRC and SAGE_LIB to turn a source filename to a qualified package name so that

• it does not fail when sage.env.SAGE_SRC cannot be imported or is empty
• it replaces the use of SAGE_LIB by using sage.__path__ (to handle namespace packages correctly)

part of Meta-ticket #33037 (Remove use of SAGE_LIB and SAGE_EXTCODE variables)

Depends on #33793

CC: @kiwifb @antonio-rojas @tornaria

Component: refactoring

Author: Matthias Koeppe

Branch/Commit: 748d9fb

Reviewer: François Bissey

Issue created by migration from https://trac.sagemath.org/ticket/33821

[mkoeppe]

Dependencies: #33793

[mkoeppe]

Branch: u/mkoeppe/remove_use_of_sage_lib_in_sage_misc

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

8cacd5e	src/sage/misc/sageinspect.py: Remove import of SAGE_LIB
c8a5bdf	src/sage/misc/lazy_import.pyx: Import lazy_import_cache only when needed
cce5385	src/sage/sets/set_from_iterator.py: Remove use of SAGE_LIB

[sagetrac-git]

Commit: cce5385

[mkoeppe]

Author: Matthias Koeppe

[mkoeppe]

Description changed:

--- 
+++ 
@@ -1 +1 @@
-
+part of Meta-ticket #33037

[sagetrac-git]

Changed commit from cce5385 to b39cf31

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

b39cf31

src/sage/misc/lazy_import.pyx: Update doctest

[mkoeppe]

comment:6

The failure in "Build&Test" is in sage -t --random-seed=54174803604868423169944467131116599504 sage/parallel/map_reduce.py , unrelated.

[sagetrac-git]

Changed commit from b39cf31 to 897e103

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

b004ca9	src/sage/misc/cachefunc.pyx: Do not fail if sage.env cannot be imported
897e103	src/sage/sets/set_from_iterator.py: Do not fail if sage.env cannot be imported

[mkoeppe]

Description changed:

--- 
+++ 
@@ -1 +1 @@
-part of Meta-ticket #33037
+part of Meta-ticket #33037 (Remove use of `SAGE_LIB` and `SAGE_EXTCODE` variables)

[mkoeppe]

Description changed:

--- 
+++ 
@@ -1 +1,7 @@
+We delay importing `lazy_import_cache` until a lazy star import is done (which the Sage library never does).
+
+We change two copies of essentially the same code that tries to use `SAGE_SRC` and `SAGE_LIB` to turn a source filename to a qualified package name so that 
+- it does not fail when `sage.env.SAGE_SRC` cannot be imported or is empty
+- it replaces the use of `SAGE_LIB` by using `sage.__path__` (to handle namespace packages correctly)
+
 part of Meta-ticket #33037 (Remove use of `SAGE_LIB` and `SAGE_EXTCODE` variables)

[kiwifb]

comment:11

You have a repeated block

+                def directories():
+                    try:
+                        from sage.env import SAGE_SRC
+                    except ImportError:
+                        pass
+                    else:
+                        if SAGE_SRC:
+                            yield normpath(os.path.join(SAGE_SRC, 'sage'))
+                    import sage
+                    yield from sage.__path__
+
+                for directory in directories():
+                    if commonprefix([filename, directory]) == directory:
+                        filename = os.path.join('sage', relpath(filename, directory))
+                        break

If it ends up being useful in more than two files, should it be factored somewhere?

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

53154b3	Merge tag '9.7.beta3' into t/33821/remove_use_of_sage_lib_in_sage_misc
748d9fb	sage.misc.sageinspect.sage_getfile_relative: New, use it in sage.misc.cachefunc, sage.sets.set_from_iterator.Decorator