fixes #643

AnswerDotAI · Oct 25, 2024 · fe31209 · fe31209
1 parent 56895f2
commit fe31209
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Showing 3 changed files with 130 additions and 5 deletions.
diff --git a/fastcore/_modidx.py b/fastcore/_modidx.py
@@ -686,6 +686,7 @@
                                 'fastcore.xtras.dataclass_src': ('xtras.html#dataclass_src', 'fastcore/xtras.py'),
                                 'fastcore.xtras.dict2obj': ('xtras.html#dict2obj', 'fastcore/xtras.py'),
                                 'fastcore.xtras.dumps': ('xtras.html#dumps', 'fastcore/xtras.py'),
+                                'fastcore.xtras.exec_eval': ('xtras.html#exec_eval', 'fastcore/xtras.py'),
                                 'fastcore.xtras.expand_wildcards': ('xtras.html#expand_wildcards', 'fastcore/xtras.py'),
                                 'fastcore.xtras.flexicache': ('xtras.html#flexicache', 'fastcore/xtras.py'),
                                 'fastcore.xtras.flexiclass': ('xtras.html#flexiclass', 'fastcore/xtras.py'),

diff --git a/fastcore/xtras.py b/fastcore/xtras.py
@@ -9,11 +9,12 @@
 __all__ = ['spark_chars', 'UNSET', 'walk', 'globtastic', 'maybe_open', 'mkdir', 'image_size', 'bunzip', 'loads', 'loads_multi',
            'dumps', 'untar_dir', 'repo_details', 'run', 'open_file', 'save_pickle', 'load_pickle', 'parse_env',
            'expand_wildcards', 'dict2obj', 'obj2dict', 'repr_dict', 'is_listy', 'mapped', 'IterLen',
-           'ReindexCollection', 'get_source_link', 'truncstr', 'sparkline', 'modify_exception', 'round_multiple',
-           'set_num_threads', 'join_path_file', 'autostart', 'EventTimer', 'stringfmt_names', 'PartialFormatter',
-           'partial_format', 'utc2local', 'local2utc', 'trace', 'modified_env', 'ContextManagers', 'shufflish',
-           'console_help', 'hl_md', 'type2str', 'dataclass_src', 'Unset', 'nullable_dc', 'make_nullable', 'flexiclass',
-           'asdict', 'is_typeddict', 'is_namedtuple', 'flexicache', 'time_policy', 'mtime_policy', 'timed_cache']
+           'ReindexCollection', 'exec_eval', 'get_source_link', 'truncstr', 'sparkline', 'modify_exception',
+           'round_multiple', 'set_num_threads', 'join_path_file', 'autostart', 'EventTimer', 'stringfmt_names',
+           'PartialFormatter', 'partial_format', 'utc2local', 'local2utc', 'trace', 'modified_env', 'ContextManagers',
+           'shufflish', 'console_help', 'hl_md', 'type2str', 'dataclass_src', 'Unset', 'nullable_dc', 'make_nullable',
+           'flexiclass', 'asdict', 'is_typeddict', 'is_namedtuple', 'flexicache', 'time_policy', 'mtime_policy',
+           'timed_cache']
 
 # %% ../nbs/03_xtras.ipynb
 from .imports import *
@@ -408,6 +409,25 @@ def __setstate__(self, s): self.coll,self.idxs,self.cache,self.tfm = s['coll'],s
                 shuffle="Randomly shuffle indices",
                 cache_clear="Clear LRU cache")
 
+# %% ../nbs/03_xtras.ipynb
+def exec_eval(code,   # Code to exec/eval
+              g=None, # Globals namespace dict
+              l=None  # Locals namespace dict
+             ):
+    "Evaluate `code` in `g` (defaults to `globals()`) and `l` (defaults to `locals()`)"
+    import ast, inspect
+    frame = inspect.currentframe().f_back
+    if l is None: l = g if g else frame.f_locals
+    if g is None: g = frame.f_globals
+    tree = ast.parse(code, mode='exec')
+    if tree.body and isinstance(tree.body[-1], ast.Expr):
+        *statements, expr = tree.body
+        exec_code = compile(ast.Module(statements, []), filename="<string>", mode="exec")
+        expr_code = compile(ast.Expression(expr.value), filename="<string>", mode="eval")
+        exec(exec_code, g, l)
+        return eval(expr_code, g, l)
+    else: exec(code, g, l)
+
 # %% ../nbs/03_xtras.ipynb
 def _is_type_dispatch(x): return type(x).__name__ == "TypeDispatch"
 def _unwrapped_type_dispatch_func(x): return x.first() if _is_type_dispatch(x) else x

diff --git a/nbs/03_xtras.ipynb b/nbs/03_xtras.ipynb
@@ -1785,6 +1785,110 @@
     "## Other Helpers"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#| export\n",
+    "def exec_eval(code,   # Code to exec/eval\n",
+    "              g=None, # Globals namespace dict\n",
+    "              l=None  # Locals namespace dict\n",
+    "             ):\n",
+    "    \"Evaluate `code` in `g` (defaults to `globals()`) and `l` (defaults to `locals()`)\"\n",
+    "    import ast, inspect\n",
+    "    frame = inspect.currentframe().f_back\n",
+    "    if l is None: l = g if g else frame.f_locals\n",
+    "    if g is None: g = frame.f_globals\n",
+    "    tree = ast.parse(code, mode='exec')\n",
+    "    if tree.body and isinstance(tree.body[-1], ast.Expr):\n",
+    "        *statements, expr = tree.body\n",
+    "        exec_code = compile(ast.Module(statements, []), filename=\"<string>\", mode=\"exec\")\n",
+    "        expr_code = compile(ast.Expression(expr.value), filename=\"<string>\", mode=\"eval\")\n",
+    "        exec(exec_code, g, l)\n",
+    "        return eval(expr_code, g, l)\n",
+    "    else: exec(code, g, l)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "This is a combination of `eval` and `exec`, which behaves like ipython and Jupyter. If the last line is an expression, it is evaluated and the result is returned:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "2"
+      ]
+     },
+     "execution_count": null,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "exec_eval('''\n",
+    "def f(x): return x+1\n",
+    "f(1)\n",
+    "''')"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "By default, the code uses the caller's globals and locals. For instance, here `f` is available since it's been added to our symbol table:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "3\n"
+     ]
+    }
+   ],
+   "source": [
+    "exec_eval('print(f(2))')"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Pass a dict as the `g` param in order to use an arbitrary namespace:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Hi I am f.\n"
+     ]
+    }
+   ],
+   "source": [
+    "exec_eval('print(f)', {'f': 'Hi I am f.'})"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,