Trac #34187: Remove src/sage/__init__.py

Follow-up from #33011.

Because of the complication described in #33011, we not only remove the
file from the source tree but also remove it from site-packages before
building sagelib.

Follow-up:
- make sagemath-standard, sage-setup depend on sagemath-environment

URL: https://trac.sagemath.org/34187
Reported by: mkoeppe
Ticket author(s): Matthias Koeppe
Reviewer(s): Kwankyu Lee

build/pkgs/sagelib/spkg-install

@@ -38,6 +38,7 @@ export SAGE_SHARE=/doesnotexist
 # export SAGE_DOC=/doesnotexist
 
 SITEPACKAGESDIR=$(python3 -c 'import sysconfig; print(sysconfig.get_paths()["purelib"])')
+
 if [ "$SAGE_EDITABLE" = yes ]; then
     # In an incremental build, we may need to uninstall old versions installed by distutils
     # under the old distribution name "sage" (before #30912, which switched to setuptools
@@ -46,6 +47,9 @@ if [ "$SAGE_EDITABLE" = yes ]; then
     (cd "$SITEPACKAGESDIR" && rm -rf sage sage_setup sage-[1-9]*.egg-info sage-[1-9]*.dist-info)
     time python3 -m pip install --verbose --no-deps --no-index --no-build-isolation --isolated --editable . || exit 1
 else
+    # Make sure that an installed old version of sagelib in which sage is an ordinary package
+    # does not shadow the namespace package sage during the build.
+    (cd "$SITEPACKAGESDIR" && rm -f sage/__init__.py)
     # Likewise, we should remove the egg-link that may have been installed previously.
     (cd "$SITEPACKAGESDIR" && rm -f sagemath-standard.egg-link)
     time python3 -u setup.py --no-user-cfg build install || exit 1

src/sage/all.py

@@ -274,6 +274,11 @@ def quit_sage(verbose=True):
 # sys.settrace(poison_currRing)
 
 
+# Deprecated leftover of monkey-patching inspect.isfunction() to support Cython functions.
+lazy_import('sage.misc.sageinspect', 'is_function_or_cython_function',
+            as_='isfunction', namespace=sage.__dict__, deprecation=32479)
+
+
 # Set a new random number seed as the very last thing
 # (so that printing initial_seed() and using that seed
 # in set_random_seed() will result in the same sequence you got at

src/sage/functions/other.py

@@ -7,8 +7,8 @@
 
     sage: from sage.functions.other import beta
     sage: beta(x, x)
-    doctest:...: DeprecationWarning:
-    Importing beta from here is deprecated. If you need to use it, please import it directly from sage.functions.gamma
+    doctest:warning...: DeprecationWarning:
+    Importing beta from here is deprecated; please use "from sage.functions.gamma import beta" instead.
     See http://trac.sagemath.org/24411 for details.
     beta(x, x)
 """

src/sage/groups/matrix_gps/homset.py

@@ -30,9 +30,8 @@ def is_MatrixGroupHomset(x):
         sage: from sage.groups.matrix_gps.homset import is_MatrixGroupHomset
         sage: is_MatrixGroupHomset(4)
         doctest:...: DeprecationWarning:
-        Importing MatrixGroupHomset from here is deprecated.
-        If you need to use it, please import it directly from
-         sage.groups.libgap_morphism
+        Importing MatrixGroupHomset from here is deprecated; please use
+        "from sage.groups.libgap_morphism import GroupHomset_libgap as MatrixGroupHomset" instead.
         See https://trac.sagemath.org/25444 for details.
         False
 

src/sage/misc/edit_module.py

@@ -75,8 +75,8 @@ def file_and_line(obj):
     EXAMPLES::
 
         sage: import sage.misc.edit_module as edit_module
-        sage: edit_module.file_and_line(sage)
-        ('...sage/__init__.py', 0)
+        sage: edit_module.file_and_line(sage.cpython)
+        ('...sage/cpython/__init__.py', 0)
 
     The following tests against a bug that was fixed in :trac:`11298`::
 

src/sage/misc/lazy_import.pyx

@@ -255,18 +255,19 @@ cdef class LazyImport():
                 raise FeatureNotPresentError(self._feature, reason=f'Importing {self._name} failed: {e}')
             raise
 
-        name = self._as_name
         if self._deprecation is not None:
             from sage.misc.superseded import deprecation_cython as deprecation
             try:
                 trac_number, message = self._deprecation
             except TypeError:
                 trac_number = self._deprecation
-                message = ('\nImporting {name} from here is deprecated. ' +
-                    'If you need to use it, please import it directly from' +
-                    ' {module_name}').format(name=name, module_name=self._module)
+                import_command = f'from {self._module} import {self._name}'
+                if self._as_name != self._name:
+                    import_command += f' as {self._as_name}'
+                message = f'\nImporting {self._as_name} from here is deprecated; please use "{import_command}" instead.'
             deprecation(trac_number, message)
         # Replace the lazy import in the namespace by the actual object
+        name = self._as_name
         if self._namespace is not None:
             if self._namespace.get(name) is self:
                 self._namespace[name] = self._object
@@ -1028,7 +1029,7 @@ def lazy_import(module, names, as_=None, *,
         sage: lazy_import('sage.all', 'Qp', 'my_Qp', deprecation=14275)
         sage: my_Qp(5)
         doctest:...: DeprecationWarning:
-        Importing my_Qp from here is deprecated. If you need to use it, please import it directly from sage.all
+        Importing my_Qp from here is deprecated; please use "from sage.all import Qp as my_Qp" instead.
         See http://trac.sagemath.org/14275 for details.
         5-adic Field with capped relative precision 20
 

src/sage/misc/sageinspect.py

@@ -2606,7 +2606,8 @@ def __internal_tests():
         sage: sage_getdoc(None)
         ''
 
-        sage: sage_getsource(sage)
+        sage: import sage.all__sagemath_objects
+        sage: sage_getsource(sage.all__sagemath_objects)
         '...all...'
 
     A cython function with default arguments (one of which is a string)::

src/sage/modular/modform/find_generators.py

@@ -21,7 +21,7 @@
     sage: find_generators(ModularFormsRing(1))
     doctest:warning
     ...
-    DeprecationWarning: Importing find_generators from here is deprecated. If you need to use it, please import it directly from sage.modular.modform.ring
+    DeprecationWarning: Importing find_generators from here is deprecated; please use "from sage.modular.modform.ring import find_generators" instead.
     See https://trac.sagemath.org/31559 for details.
     [(4,
     1 + 240*q + 2160*q^2 + 6720*q^3 + 17520*q^4 + 30240*q^5 + 60480*q^6 + 82560*q^7 + 140400*q^8 + 181680*q^9 + O(q^10)),
@@ -45,7 +45,7 @@
     sage: _span_of_forms_in_weight(forms, 12, prec=5)
     doctest:warning
     ...
-    DeprecationWarning: Importing _span_of_forms_in_weight from here is deprecated. If you need to use it, please import it directly from sage.modular.modform.ring
+    DeprecationWarning: Importing _span_of_forms_in_weight from here is deprecated; please use "from sage.modular.modform.ring import _span_of_forms_in_weight" instead.
     See https://trac.sagemath.org/31559 for details.
     Vector space of degree 5 and dimension 2 over Rational Field
     Basis matrix:

src/sage/rings/all.py

@@ -6,19 +6,22 @@
     sage: PowerSeries
     doctest:warning...:
     DeprecationWarning:
-    Importing PowerSeries from here is deprecated. If you need to use it, please import it directly from sage.rings.power_series_ring_element
+    Importing PowerSeries from here is deprecated;
+    please use "from sage.rings.power_series_ring_element import PowerSeries" instead.
     See https://trac.sagemath.org/33602 for details.
     ...
     sage: PuiseuxSeries
     doctest:warning...:
     DeprecationWarning:
-    Importing PuiseuxSeries from here is deprecated. If you need to use it, please import it directly from sage.rings.puiseux_series_ring_element
+    Importing PuiseuxSeries from here is deprecated;
+    please use "from sage.rings.puiseux_series_ring_element import PuiseuxSeries" instead.
     See https://trac.sagemath.org/33602 for details.
     ...
     sage: LaurentSeries
     doctest:warning...:
     DeprecationWarning:
-    Importing LaurentSeries from here is deprecated. If you need to use it, please import it directly from sage.rings.laurent_series_ring_element
+    Importing LaurentSeries from here is deprecated;
+    please use "from sage.rings.laurent_series_ring_element import LaurentSeries" instead.
     See https://trac.sagemath.org/33602 for details.
     ...
 """

src/sage/schemes/hyperelliptic_curves/all.py

@@ -4,28 +4,32 @@
     sage: igusa_clebsch_invariants
     doctest:warning...:
     DeprecationWarning:
-    Importing igusa_clebsch_invariants from here is deprecated. If you need to use it, please import it directly from sage.schemes.hyperelliptic_curves.invariants
+    Importing igusa_clebsch_invariants from here is deprecated;
+    please use "from sage.schemes.hyperelliptic_curves.invariants import igusa_clebsch_invariants" instead.
     See https://trac.sagemath.org/28064 for details.
     ...
 
     sage: absolute_igusa_invariants_kohel
     doctest:warning...:
     DeprecationWarning:
-    Importing absolute_igusa_invariants_kohel from here is deprecated. If you need to use it, please import it directly from sage.schemes.hyperelliptic_curves.invariants
+    Importing absolute_igusa_invariants_kohel from here is deprecated;
+    please use "from sage.schemes.hyperelliptic_curves.invariants import absolute_igusa_invariants_kohel" instead.
     See https://trac.sagemath.org/28064 for details.
     ...
 
     sage: absolute_igusa_invariants_wamelen
     doctest:warning...:
     DeprecationWarning:
-    Importing absolute_igusa_invariants_wamelen from here is deprecated. If you need to use it, please import it directly from sage.schemes.hyperelliptic_curves.invariants
+    Importing absolute_igusa_invariants_wamelen from here is deprecated;
+    please use "from sage.schemes.hyperelliptic_curves.invariants import absolute_igusa_invariants_wamelen" instead.
     See https://trac.sagemath.org/28064 for details.
     ...
 
     sage: clebsch_invariants
     doctest:warning...:
     DeprecationWarning:
-    Importing clebsch_invariants from here is deprecated. If you need to use it, please import it directly from sage.schemes.hyperelliptic_curves.invariants
+    Importing clebsch_invariants from here is deprecated;
+    please use "from sage.schemes.hyperelliptic_curves.invariants import clebsch_invariants" instead.
     See https://trac.sagemath.org/28064 for details.
     ...
 """

src/sage/tests/books/computational-mathematics-with-sagemath/graphique_doctest.py

@@ -71,10 +71,10 @@
   DeprecationWarning: the package sage.finance is deprecated
   See https://trac.sagemath.org/32427 for details.
   doctest:warning...
-  Importing finance from here is deprecated. If you need to use it, please import it directly from sage.finance
+  Importing finance from here is deprecated; please use "from sage.finance import all as finance" instead.
   See https://trac.sagemath.org/32427 for details.
   doctest:warning...
-  Importing TimeSeries from here is deprecated. If you need to use it, please import it directly from sage.stats.time_series
+  Importing TimeSeries from here is deprecated; please use "from sage.stats.time_series import TimeSeries" instead.
   See https://trac.sagemath.org/32427 for details.
   Graphics object consisting of 20 graphics primitives
 

src/sage_setup/find.py

@@ -274,8 +274,9 @@ def _cythonized_dir(src_dir=None, editable_install=None):
         if src_dir is None:
             src_dir = SAGE_SRC
         src_dir = Path(src_dir)
-        sage = import_module('sage')
-        d = Path(sage.__file__).resolve().parent.parent
+        # sage.cpython is an ordinary package, so it has __file__
+        sage_cpython = import_module('sage.cpython')
+        d = Path(sage_cpython.__file__).resolve().parent.parent.parent
         editable_install = d == src_dir.resolve()
     if editable_install:
         # Editable install: Cython generates files in the source tree
@@ -390,7 +391,7 @@ def installed_files_by_module(site_packages, modules=('sage',)):
 
     EXAMPLES::
 
-        sage: site_packages = os.path.dirname(os.path.dirname(sage.__file__))
+        sage: site_packages = os.path.dirname(os.path.dirname(os.path.dirname(sage.cpython.__file__)))
         sage: from sage_setup.find import installed_files_by_module
         sage: files_by_module = installed_files_by_module(site_packages)
         sage: (f,) = files_by_module['sage.structure.sage_object']; f