gh-107944: Improve error message for function calls with bad keyword arguments (#107969)

1 files changed, 28 insertions, 3 deletions

diff --git a/Python/ceval.c b/Python/ceval.c
index 329a1a1..f7dfaeb 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -26,6 +26,7 @@
 #include "pycore_tuple.h"         // _PyTuple_ITEMS()
 #include "pycore_typeobject.h"    // _PySuper_Lookup()
 #include "pycore_uops.h"          // _PyUOpExecutorObject
+#include "pycore_pyerrors.h"
 
 #include "pycore_dict.h"
 #include "dictobject.h"
@@ -1337,9 +1338,33 @@ initialize_locals(PyThreadState *tstate, PyFunctionObject *func,
                     goto kw_fail;
                 }
 
-                _PyErr_Format(tstate, PyExc_TypeError,
-                            "%U() got an unexpected keyword argument '%S'",
-                          func->func_qualname, keyword);
+                PyObject* suggestion_keyword = NULL;
+                if (total_args > co->co_posonlyargcount) {
+                    PyObject* possible_keywords = PyList_New(total_args - co->co_posonlyargcount);
+
+                    if (!possible_keywords) {
+                        PyErr_Clear();
+                    } else {
+                        for (Py_ssize_t k = co->co_posonlyargcount; k < total_args; k++) {
+                            PyList_SET_ITEM(possible_keywords, k - co->co_posonlyargcount, co_varnames[k]);
+                        }
+
+                        suggestion_keyword = _Py_CalculateSuggestions(possible_keywords, keyword);
+                        Py_DECREF(possible_keywords);
+                    }
+                }
+
+                if (suggestion_keyword) {
+                    _PyErr_Format(tstate, PyExc_TypeError,
+                                "%U() got an unexpected keyword argument '%S'. Did you mean '%S'?",
+                                func->func_qualname, keyword, suggestion_keyword);
+                    Py_DECREF(suggestion_keyword);
+                } else {
+                    _PyErr_Format(tstate, PyExc_TypeError,
+                                "%U() got an unexpected keyword argument '%S'",
+                                func->func_qualname, keyword);
+                }
+
                 goto kw_fail;
             }