1.3.0 - The init file has been improved so as not to export symbols from other packages. Fixes #6

Author: smarie

docs/changelog.md

@@ -1,3 +1,7 @@
+### 1.3.0 - fixed init.py
+
+ * The init file has been improved so as not to export symbols from other packages. Fixes [#6](https://github.com/smarie/python-mini-lambda/issues/6)
+
 ### 1.2.4 - Minor improvements in generated goodies
 
  * Removed annoying warning message when loading goodies

mini_lambda/__init__.py

@@ -1,5 +1,18 @@
-# allow users to do
-#     from mini_lambda import xxx
+from mini_lambda.utils_init import __remove_all_external_symbols, __get_all_submodules_symbols
+
+__PACKAGE_NAME = 'mini_lambda'
+__SUBMODULES_TO_EXPORT = ['base', 'generated', 'generated2', 'goodies', 'goodies_generated', 'main']
+# TODO we could rather rely on a regexp mechanism
+
+# (1) allow users to do
+#     import <package> as p and then p.<symbol>
+__all__ = __get_all_submodules_symbols(__PACKAGE_NAME, __SUBMODULES_TO_EXPORT)
+# Note: this is one way to do it, but it would be simpler to check the names in globals() at the end of this file.
+
+# (2) allow users to do
+#     from <package> import <symbol>
+#
+# The following works, but unfortunately IDE like pycharm do not understand
 from mini_lambda.base import *
 from mini_lambda.generated import *
 from mini_lambda.goodies_generated import *
@@ -8,6 +21,13 @@
 from mini_lambda.generated2 import *
 from mini_lambda.goodies import *
 
-# allow users to do
-#     import mini_lambda as v
-__all__ = ['base', 'generated', 'goodies_generated', 'main', 'generated2', 'goodies']
+# remove all symbols that were imported above but do not belong in this package
+__remove_all_external_symbols(__PACKAGE_NAME, globals())
+
+# Otherwise exhaustive list would be required, which is sad
+# ...
+
+# print(__all__)
+# print(globals().keys())
+# print('Done')
+

mini_lambda/tests/test_packaging.py

@@ -0,0 +1,8 @@
+
+def test_named_import():
+    import mini_lambda as ml
+    o = ml.InputVar
+
+
+def test_import_from():
+    from mini_lambda import InputVar

mini_lambda/tests/test_packaging_wild.py

@@ -0,0 +1,5 @@
+from mini_lambda import *  # this relies on '__all__'
+
+
+def test_wild_import():
+    o = InputVar

mini_lambda/utils_init.py

@@ -0,0 +1,60 @@
+def __is_defined_in_submodule(submodule_name_prefix, x):
+    """
+    Utility method to return True if x is not a module and its module name starts with submodule_name_prefix
+    e.g. 'autoclass.autohash_'.
+
+    :param submodule_name_prefix:
+    :param x:
+    :return:
+    """
+    # if _inspect.ismodule(x):
+    #     return False
+    # else:
+    from inspect import getmodule
+    m = getmodule(x)
+    if m is None:
+        return True
+    elif hasattr(m, '__name__') and m.__name__.startswith(submodule_name_prefix):
+        return True
+    else:
+        return False
+
+
+def __get_all_submodules_symbols(pkg_name, submodules_to_export):
+    """
+    Generates the list of symbol names that can be used in the `__all__` variable in init.py
+    The list is created from a list of submodules.
+
+    All symbols in these submodules that are not private and that are actually defined in there, get in the list.
+    The submodules themselves end up in the list.
+
+    Note that this function should only be used if you also actually import those symbols in the init.py, so that they
+    are actually visible at package root level.
+
+    :param submodules_to_export: a list of submodule names to export
+    :return:
+    """
+    from inspect import getmembers
+    from copy import copy
+    from importlib import import_module
+
+    # first create a copy of the submodules list
+    all_ = copy(submodules_to_export)
+
+    # then for each submodule add the symbols that are declared in this submodule
+    for submodule in submodules_to_export:
+        submodule_full_name = pkg_name + '.' + submodule
+        imported_module = import_module(submodule_full_name)
+        # print(imported_module.__name__)
+        for x_name, symbol in getmembers(imported_module):
+            if not x_name.startswith('_'):
+                if __is_defined_in_submodule(submodule_full_name, symbol):
+                    # print('{} is exported'.format(x_name))
+                    all_.append(x_name)
+    return all_
+
+
+def __remove_all_external_symbols(pkg_name, globs):
+    for x_name in list(globs.keys()):
+        if not __is_defined_in_submodule(pkg_name, globs[x_name]):
+            del globs[x_name]