use inspect in Foundation

Author: jph00

fastcore/foundation.py

@@ -10,7 +10,7 @@
 from contextlib import contextmanager
 from copy import copy
 from configparser import ConfigParser
-import random,pickle
+import random,pickle,inspect
 
 # Cell
 @contextmanager
@@ -222,7 +222,10 @@ def setattrs(self, attr, val): [setattr(o,attr,val) for o in self]
 
 # Cell
 #hide
-L.__signature__ = pickle.loads(b'\x80\x03cinspect\nSignature\nq\x00(cinspect\nParameter\nq\x01X\x05\x00\x00\x00itemsq\x02cinspect\n_ParameterKind\nq\x03K\x01\x85q\x04Rq\x05\x86q\x06Rq\x07}q\x08(X\x08\x00\x00\x00_defaultq\tNX\x0b\x00\x00\x00_annotationq\ncinspect\n_empty\nq\x0bubh\x01X\x04\x00\x00\x00restq\x0ch\x03K\x02\x85q\rRq\x0e\x86q\x0fRq\x10}q\x11(h\th\x0bh\nh\x0bubh\x01X\x08\x00\x00\x00use_listq\x12h\x03K\x03\x85q\x13Rq\x14\x86q\x15Rq\x16}q\x17(h\t\x89h\nh\x0bubh\x01X\x05\x00\x00\x00matchq\x18h\x14\x86q\x19Rq\x1a}q\x1b(h\tNh\nh\x0bubtq\x1c\x85q\x1dRq\x1e}q\x1fX\x12\x00\x00\x00_return_annotationq h\x0bsb.')
+# Here we are fixing the signature of L. What happens is that the __call__ method on the MetaClass of L shadows the __init__
+# giving the wrong signature (https://stackoverflow.com/questions/49740290/call-from-metaclass-shadows-signature-of-init).
+def _f(items=None, *rest, use_list=False, match=None): ...
+L.__signature__ = inspect.signature(_f)
 
 # Cell
 Sequence.register(L);

nbs/02_foundation.ipynb

@@ -22,7 +22,7 @@
     "from contextlib import contextmanager\n",
     "from copy import copy\n",
     "from configparser import ConfigParser\n",
-    "import random,pickle"
+    "import random,pickle,inspect"
    ]
   },
   {
@@ -33,8 +33,7 @@
    "source": [
     "from fastcore.test import *\n",
     "from nbdev.showdoc import *\n",
-    "from fastcore.nb_imports import *\n",
-    "import inspect"
+    "from fastcore.nb_imports import *"
    ]
   },
   {
@@ -681,39 +680,14 @@
    "cell_type": "code",
    "execution_count": null,
    "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/plain": [
-       "b'\\x80\\x03cinspect\\nSignature\\nq\\x00(cinspect\\nParameter\\nq\\x01X\\x05\\x00\\x00\\x00itemsq\\x02cinspect\\n_ParameterKind\\nq\\x03K\\x01\\x85q\\x04Rq\\x05\\x86q\\x06Rq\\x07}q\\x08(X\\x08\\x00\\x00\\x00_defaultq\\tNX\\x0b\\x00\\x00\\x00_annotationq\\ncinspect\\n_empty\\nq\\x0bubh\\x01X\\x04\\x00\\x00\\x00restq\\x0ch\\x03K\\x02\\x85q\\rRq\\x0e\\x86q\\x0fRq\\x10}q\\x11(h\\th\\x0bh\\nh\\x0bubh\\x01X\\x08\\x00\\x00\\x00use_listq\\x12h\\x03K\\x03\\x85q\\x13Rq\\x14\\x86q\\x15Rq\\x16}q\\x17(h\\t\\x89h\\nh\\x0bubh\\x01X\\x05\\x00\\x00\\x00matchq\\x18h\\x14\\x86q\\x19Rq\\x1a}q\\x1b(h\\tNh\\nh\\x0bubtq\\x1c\\x85q\\x1dRq\\x1e}q\\x1fX\\x12\\x00\\x00\\x00_return_annotationq h\\x0bsb.'"
-      ]
-     },
-     "execution_count": null,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
+   "outputs": [],
    "source": [
+    "#export\n",
     "#hide\n",
     "# Here we are fixing the signature of L. What happens is that the __call__ method on the MetaClass of L shadows the __init__\n",
     "# giving the wrong signature (https://stackoverflow.com/questions/49740290/call-from-metaclass-shadows-signature-of-init).\n",
-    "#\n",
-    "# The solution adopted tries to not import the inspect module inside the lib code (notice that this cell is not exported)\n",
-    "# because it's really slow, but instead relies on pickling the correct signature and loading it.\n",
-    "\n",
     "def _f(items=None, *rest, use_list=False, match=None): ...\n",
-    "pickle.dumps(inspect.signature(_f))"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "#export\n",
-    "#hide\n",
-    "L.__signature__ = pickle.loads(b'\\x80\\x03cinspect\\nSignature\\nq\\x00(cinspect\\nParameter\\nq\\x01X\\x05\\x00\\x00\\x00itemsq\\x02cinspect\\n_ParameterKind\\nq\\x03K\\x01\\x85q\\x04Rq\\x05\\x86q\\x06Rq\\x07}q\\x08(X\\x08\\x00\\x00\\x00_defaultq\\tNX\\x0b\\x00\\x00\\x00_annotationq\\ncinspect\\n_empty\\nq\\x0bubh\\x01X\\x04\\x00\\x00\\x00restq\\x0ch\\x03K\\x02\\x85q\\rRq\\x0e\\x86q\\x0fRq\\x10}q\\x11(h\\th\\x0bh\\nh\\x0bubh\\x01X\\x08\\x00\\x00\\x00use_listq\\x12h\\x03K\\x03\\x85q\\x13Rq\\x14\\x86q\\x15Rq\\x16}q\\x17(h\\t\\x89h\\nh\\x0bubh\\x01X\\x05\\x00\\x00\\x00matchq\\x18h\\x14\\x86q\\x19Rq\\x1a}q\\x1b(h\\tNh\\nh\\x0bubtq\\x1c\\x85q\\x1dRq\\x1e}q\\x1fX\\x12\\x00\\x00\\x00_return_annotationq h\\x0bsb.')"
+    "L.__signature__ = inspect.signature(_f)"
    ]
   },
   {

nbs/04_dispatch.ipynb

@@ -26,9 +26,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "metadata": {
-    "tags": []
-   },
+   "metadata": {},
    "outputs": [],
    "source": [
     "from nbdev.showdoc import *\n",