fix: Give __name__ to executed Python "modules", and populate `sys.…

…modules` too

Issue-47: #47

src/markdown_exec/formatters/python.py

@@ -2,10 +2,13 @@
 
 from __future__ import annotations
 
+import re
+import sys
 import traceback
 from collections import defaultdict
 from functools import partial
 from io import StringIO
+from types import ModuleType
 from typing import Any
 
 from markdown_exec.formatters.base import ExecutionError, base_format
@@ -51,6 +54,15 @@ def _run_python(
     _code_blocks[code_block_id] = code.split("\n")
     exec_globals = _sessions_globals[session] if session else {}
 
+    # Other libraries expect functions to have a valid `__module__` attribute.
+    # To achieve this, we need to add a `__name__` attribute to the globals.
+    # We compute the name from the code block ID, replacing invalid characters with `_`.
+    # We also create a module object with the same name and add it to `sys.modules`,
+    # because that's what yet other libraries expect (`dataclasses` for example).
+    module_name = re.sub(r"[^a-zA-Z\d]+", "_", code_block_id)
+    exec_globals["__name__"] = module_name
+    sys.modules[module_name] = ModuleType(module_name)
+
     buffer = StringIO()
     exec_globals["print"] = partial(_buffer_print, buffer)
 

tests/test_python.py

@@ -182,3 +182,24 @@ def test_removing_output_from_pycon_code(md: Markdown) -> None:
     )
     assert "ok" in html
     assert "ko" not in html
+
+
+def test_functions_have_a_module_attribute(md: Markdown) -> None:
+    """Assert functions have a `__module__` attribute.
+
+    Parameters:
+        md: A Markdown instance (fixture).
+    """
+    html = md.convert(
+        dedent(
+            """
+            ```python exec="1"
+            def func():
+                pass
+
+            print(f"`{func.__module__}`")
+            ```
+            """,
+        ),
+    )
+    assert "_code_block_n" in html