bpo-4356: Add key function support to the bisect module (GH-20556)

Doc/library/bisect.rst

@@ -21,7 +21,7 @@ example of the algorithm (the boundary conditions are already right!).
 The following functions are provided:
 
 
-.. function:: bisect_left(a, x, lo=0, hi=len(a))
+.. function:: bisect_left(a, x, lo=0, hi=len(a), *, key=None)
 
    Locate the insertion point for *x* in *a* to maintain sorted order.
    The parameters *lo* and *hi* may be used to specify a subset of the list
@@ -31,39 +31,106 @@ The following functions are provided:
    parameter to ``list.insert()`` assuming that *a* is already sorted.
 
    The returned insertion point *i* partitions the array *a* into two halves so
-   that ``all(val < x for val in a[lo:i])`` for the left side and
+   that ``all(val < x for val in a[lo : i])`` for the left side and
-   ``all(val >= x for val in a[i:hi])`` for the right side.
+   ``all(val >= x for val in a[i : hi])`` for the right side.
 
-.. function:: bisect_right(a, x, lo=0, hi=len(a))
+   *key* specifies a :term:`key function` of one argument that is used to
+   extract a comparison key from each input element.  The default value is
+   ``None`` (compare the elements directly).
+
+   .. versionchanged:: 3.10
+      Added the *key* parameter.
+
+
+.. function:: bisect_right(a, x, lo=0, hi=len(a), *, key=None)
               bisect(a, x, lo=0, hi=len(a))
 
    Similar to :func:`bisect_left`, but returns an insertion point which comes
    after (to the right of) any existing entries of *x* in *a*.
 
    The returned insertion point *i* partitions the array *a* into two halves so
-   that ``all(val <= x for val in a[lo:i])`` for the left side and
+   that ``all(val <= x for val in a[lo : i])`` for the left side and
-   ``all(val > x for val in a[i:hi])`` for the right side.
+   ``all(val > x for val in a[i : hi])`` for the right side.
 
-.. function:: insort_left(a, x, lo=0, hi=len(a))
+   *key* specifies a :term:`key function` of one argument that is used to
+   extract a comparison key from each input element.  The default value is
+   ``None`` (compare the elements directly).
 
-   Insert *x* in *a* in sorted order.  This is equivalent to
+   .. versionchanged:: 3.10
-   ``a.insert(bisect.bisect_left(a, x, lo, hi), x)`` assuming that *a* is
+      Added the *key* parameter.
-   already sorted.  Keep in mind that the O(log n) search is dominated by
-   the slow O(n) insertion step.
 
-.. function:: insort_right(a, x, lo=0, hi=len(a))
+
+.. function:: insort_left(a, x, lo=0, hi=len(a), *, key=None)
+
+   Insert *x* in *a* in sorted order.
+
+   *key* specifies a :term:`key function` of one argument that is used to
+   extract a comparison key from each input element.  The default value is
+   ``None`` (compare the elements directly).
+
+   This function first runs :func:`bisect_left` to locate an insertion point.
+   Next, it runs the :meth:`insert` method on *a* to insert *x* at the
+   appropriate position to maintain sort order.
+
+   Keep in mind that the ``O(log n)`` search is dominated by the slow O(n)
+   insertion step.
+
+   .. versionchanged:: 3.10
+      Added the *key* parameter.
+
+
+.. function:: insort_right(a, x, lo=0, hi=len(a), *, key=None)
               insort(a, x, lo=0, hi=len(a))
 
    Similar to :func:`insort_left`, but inserting *x* in *a* after any existing
    entries of *x*.
 
+   *key* specifies a :term:`key function` of one argument that is used to
+   extract a comparison key from each input element.  The default value is
+   ``None`` (compare the elements directly).
+
+   This function first runs :func:`bisect_right` to locate an insertion point.
+   Next, it runs the :meth:`insert` method on *a* to insert *x* at the
+   appropriate position to maintain sort order.
+
+   Keep in mind that the ``O(log n)`` search is dominated by the slow O(n)
+   insertion step.
+
+   .. versionchanged:: 3.10
+      Added the *key* parameter.
+
+
+Performance Notes
+-----------------
+
+When writing time sensitive code using *bisect()* and *insort()*, keep these
+thoughts in mind:
+
+* Bisection is effective for searching ranges of values.
+  For locating specific values, dictionaries are more performant.
+
+* The *insort()* functions are ``O(n)`` because the logarithmic search step
+  is dominated by the linear time insertion step.
+
+* The search functions are stateless and discard key function results after
+  they are used.  Consequently, if the search functions are used in a loop,
+  the key function may be called again and again on the same array elements.
+  If the key function isn't fast, consider wrapping it with
+  :func:`functools.cache` to avoid duplicate computations.  Alternatively,
+  consider searching an array of precomputed keys to locate the insertion
+  point (as shown in the examples section below).
+
 .. seealso::
 
-   `SortedCollection recipe
+   * `Sorted Collections
-   <https://code.activestate.com/recipes/577197-sortedcollection/>`_ that uses
+     <http://www.grantjenks.com/docs/sortedcollections/>`_ is a high performance
-   bisect to build a full-featured collection class with straight-forward search
+     module that uses *bisect* to managed sorted collections of data.
-   methods and support for a key-function.  The keys are precomputed to save
+
-   unnecessary calls to the key function during searches.
+   * The `SortedCollection recipe
+     <https://code.activestate.com/recipes/577197-sortedcollection/>`_ uses
+     bisect to build a full-featured collection class with straight-forward search
+     methods and support for a key-function.  The keys are precomputed to save
+     unnecessary calls to the key function during searches.
 
 
 Searching Sorted Lists
@@ -110,8 +177,8 @@ lists::
         raise ValueError
 
 
-Other Examples
+Examples
---------------
+--------
 
 .. _bisect-example:
 
@@ -127,17 +194,12 @@ a 'B', and so on::
    >>> [grade(score) for score in [33, 99, 77, 70, 89, 90, 100]]
    ['F', 'A', 'C', 'C', 'B', 'A', 'A']
 
-Unlike the :func:`sorted` function, it does not make sense for the :func:`bisect`
+One technique to avoid repeated calls to a key function is to search a list of
-functions to have *key* or *reversed* arguments because that would lead to an
+precomputed keys to find the index of a record::
-inefficient design (successive calls to bisect functions would not "remember"
-all of the previous key lookups).
-
-Instead, it is better to search a list of precomputed keys to find the index
-of the record in question::
 
     >>> data = [('red', 5), ('blue', 1), ('yellow', 8), ('black', 0)]
-    >>> data.sort(key=lambda r: r[1])
+    >>> data.sort(key=lambda r: r[1])       # Or use operator.itemgetter(1).
-    >>> keys = [r[1] for r in data]         # precomputed list of keys
+    >>> keys = [r[1] for r in data]         # Precompute a list of keys.
     >>> data[bisect_left(keys, 0)]
     ('black', 0)
     >>> data[bisect_left(keys, 1)]

Doc/tools/susp-ignored.csv

@@ -111,8 +111,6 @@ howto/urllib2,,:password,"""joe:password@example.com"""
 library/ast,,:upper,lower:upper
 library/ast,,:step,lower:upper:step
 library/audioop,,:ipos,"# factor = audioop.findfactor(in_test[ipos*2:ipos*2+len(out_test)],"
-library/bisect,32,:hi,all(val >= x for val in a[i:hi])
-library/bisect,42,:hi,all(val > x for val in a[i:hi])
 library/configparser,,:home,my_dir: ${Common:home_dir}/twosheds
 library/configparser,,:option,${section:option}
 library/configparser,,:path,python_dir: ${Frameworks:path}/Python/Versions/${Frameworks:Python}

Lib/bisect.py

@@ -1,6 +1,7 @@
 """Bisection algorithms."""
 
-def insort_right(a, x, lo=0, hi=None):
+
+def insort_right(a, x, lo=0, hi=None, *, key=None):
     """Insert item x in list a, and keep it sorted assuming a is sorted.
 
     If x is already in a, insert it to the right of the rightmost x.
@@ -8,11 +9,14 @@ def insort_right(a, x, lo=0, hi=None):
     Optional args lo (default 0) and hi (default len(a)) bound the
     slice of a to be searched.
     """
-
+    if key is None:
-    lo = bisect_right(a, x, lo, hi)
+        lo = bisect_right(a, x, lo, hi)
+    else:
+        lo = bisect_right(a, key(x), lo, hi, key=key)
     a.insert(lo, x)
 
-def bisect_right(a, x, lo=0, hi=None):
+
+def bisect_right(a, x, lo=0, hi=None, *, key=None):
     """Return the index where to insert item x in list a, assuming a is sorted.
 
     The return value i is such that all e in a[:i] have e <= x, and all e in
@@ -27,14 +31,26 @@ def bisect_right(a, x, lo=0, hi=None):
         raise ValueError('lo must be non-negative')
     if hi is None:
         hi = len(a)
-    while lo < hi:
+    # Note, the comparison uses "<" to match the
-        mid = (lo+hi)//2
+    # __lt__() logic in list.sort() and in heapq.
-        # Use __lt__ to match the logic in list.sort() and in heapq
+    if key is None:
-        if x < a[mid]: hi = mid
+        while lo < hi:
-        else: lo = mid+1
+            mid = (lo + hi) // 2
+            if x < a[mid]:
+                hi = mid
+            else:
+                lo = mid + 1
+    else:
+        while lo < hi:
+            mid = (lo + hi) // 2
+            if x < key(a[mid]):
+                hi = mid
+            else:
+                lo = mid + 1
     return lo
 
-def insort_left(a, x, lo=0, hi=None):
+
+def insort_left(a, x, lo=0, hi=None, *, key=None):
     """Insert item x in list a, and keep it sorted assuming a is sorted.
 
     If x is already in a, insert it to the left of the leftmost x.
@@ -43,11 +59,13 @@ def insort_left(a, x, lo=0, hi=None):
     slice of a to be searched.
     """
 
-    lo = bisect_left(a, x, lo, hi)
+    if key is None:
+        lo = bisect_left(a, x, lo, hi)
+    else:
+        lo = bisect_left(a, key(x), lo, hi, key=key)
     a.insert(lo, x)
 
-
+def bisect_left(a, x, lo=0, hi=None, *, key=None):
-def bisect_left(a, x, lo=0, hi=None):
     """Return the index where to insert item x in list a, assuming a is sorted.
 
     The return value i is such that all e in a[:i] have e < x, and all e in
@@ -62,13 +80,25 @@ def bisect_left(a, x, lo=0, hi=None):
         raise ValueError('lo must be non-negative')
     if hi is None:
         hi = len(a)
-    while lo < hi:
+    # Note, the comparison uses "<" to match the
-        mid = (lo+hi)//2
+    # __lt__() logic in list.sort() and in heapq.
-        # Use __lt__ to match the logic in list.sort() and in heapq
+    if key is None:
-        if a[mid] < x: lo = mid+1
+        while lo < hi:
-        else: hi = mid
+            mid = (lo + hi) // 2
+            if a[mid] < x:
+                lo = mid + 1
+            else:
+                hi = mid
+    else:
+        while lo < hi:
+            mid = (lo + hi) // 2
+            if key(a[mid]) < x:
+                lo = mid + 1
+            else:
+                hi = mid
     return lo
 
+
 # Overwrite above definitions with a fast C implementation
 try:
     from _bisect import *

Lib/test/test_bisect.py

@@ -200,6 +200,63 @@ class TestBisect:
         self.module.insort(a=data, x=25, lo=1, hi=3)
         self.assertEqual(data, [10, 20, 25, 25, 25, 30, 40, 50])
 
+    def test_lookups_with_key_function(self):
+        mod = self.module
+
+        # Invariant: Index with a keyfunc on an array
+        # should match the index on an array where
+        # key function has already been applied.
+
+        keyfunc = abs
+        arr = sorted([2, -4, 6, 8, -10], key=keyfunc)
+        precomputed_arr = list(map(keyfunc, arr))
+        for x in precomputed_arr:
+            self.assertEqual(
+                mod.bisect_left(arr, x, key=keyfunc),
+                mod.bisect_left(precomputed_arr, x)
+            )
+            self.assertEqual(
+                mod.bisect_right(arr, x, key=keyfunc),
+                mod.bisect_right(precomputed_arr, x)
+            )
+
+        keyfunc = str.casefold
+        arr = sorted('aBcDeEfgHhiIiij', key=keyfunc)
+        precomputed_arr = list(map(keyfunc, arr))
+        for x in precomputed_arr:
+            self.assertEqual(
+                mod.bisect_left(arr, x, key=keyfunc),
+                mod.bisect_left(precomputed_arr, x)
+            )
+            self.assertEqual(
+                mod.bisect_right(arr, x, key=keyfunc),
+                mod.bisect_right(precomputed_arr, x)
+            )
+
+    def test_insort(self):
+        from random import shuffle
+        mod = self.module
+
+        # Invariant:  As random elements are inserted in
+        # a target list, the targetlist remains sorted.
+        keyfunc = abs
+        data = list(range(-10, 11)) + list(range(-20, 20, 2))
+        shuffle(data)
+        target = []
+        for x in data:
+            mod.insort_left(target, x, key=keyfunc)
+            self.assertEqual(
+                sorted(target, key=keyfunc),
+                target
+            )
+        target = []
+        for x in data:
+            mod.insort_right(target, x, key=keyfunc)
+            self.assertEqual(
+                sorted(target, key=keyfunc),
+                target
+            )
+
 class TestBisectPython(TestBisect, unittest.TestCase):
     module = py_bisect
 

Misc/NEWS.d/next/Library/2020-05-31-10-48-47.bpo-4356.P8kXqp.rst

@@ -0,0 +1 @@
+Add a key function to the bisect module.

Modules/_bisectmodule.c

@@ -16,7 +16,8 @@ module _bisect
 _Py_IDENTIFIER(insert);
 
 static inline Py_ssize_t
-internal_bisect_right(PyObject *list, PyObject *item, Py_ssize_t lo, Py_ssize_t hi)
+internal_bisect_right(PyObject *list, PyObject *item, Py_ssize_t lo, Py_ssize_t hi,
+                      PyObject* key)
 {
     PyObject *litem;
     Py_ssize_t mid;
@@ -39,6 +40,14 @@ internal_bisect_right(PyObject *list, PyObject *item, Py_ssize_t lo, Py_ssize_t
         litem = PySequence_GetItem(list, mid);
         if (litem == NULL)
             return -1;
+        if (key != Py_None) {
+            PyObject *newitem = PyObject_CallOneArg(key, litem);
+            if (newitem == NULL) {
+                Py_DECREF(litem);
+                return -1;
+            }
+            Py_SETREF(litem, newitem);
+        }
         res = PyObject_RichCompareBool(item, litem, Py_LT);
         Py_DECREF(litem);
         if (res < 0)
@@ -58,6 +67,8 @@ _bisect.bisect_right -> Py_ssize_t
     x: object
     lo: Py_ssize_t = 0
     hi: Py_ssize_t(c_default='-1', accept={int, NoneType}) = None
+    *
+    key: object = None
 
 Return the index where to insert item x in list a, assuming a is sorted.
 
@@ -71,10 +82,10 @@ slice of a to be searched.
 
 static Py_ssize_t
 _bisect_bisect_right_impl(PyObject *module, PyObject *a, PyObject *x,
-                          Py_ssize_t lo, Py_ssize_t hi)
+                          Py_ssize_t lo, Py_ssize_t hi, PyObject *key)
-/*[clinic end generated code: output=419e150cf1d2a235 input=e72212b282c83375]*/
+/*[clinic end generated code: output=3a4bc09cc7c8a73d input=1313e9ca20c8bc3c]*/
 {
-    return internal_bisect_right(a, x, lo, hi);
+    return internal_bisect_right(a, x, lo, hi, key);
 }
 
 /*[clinic input]
@@ -84,6 +95,8 @@ _bisect.insort_right
     x: object
     lo: Py_ssize_t = 0
     hi: Py_ssize_t(c_default='-1', accept={int, NoneType}) = None
+    *
+    key: object = None
 
 Insert item x in list a, and keep it sorted assuming a is sorted.
 
@@ -95,11 +108,22 @@ slice of a to be searched.
 
 static PyObject *
 _bisect_insort_right_impl(PyObject *module, PyObject *a, PyObject *x,
-                          Py_ssize_t lo, Py_ssize_t hi)
+                          Py_ssize_t lo, Py_ssize_t hi, PyObject *key)
-/*[clinic end generated code: output=c2caa3d4cd02035a input=d1c45bfa68182669]*/
+/*[clinic end generated code: output=ac3bf26d07aedda2 input=44e1708e26b7b802]*/
 {
-    PyObject *result;
+    PyObject *result, *key_x;
-    Py_ssize_t index = internal_bisect_right(a, x, lo, hi);
+    Py_ssize_t index;
+
+    if (key == Py_None) {
+        index = internal_bisect_right(a, x, lo, hi, key);
+    } else {
+        key_x = PyObject_CallOneArg(key, x);
+        if (x == NULL) {
+            return NULL;
+        }
+        index = internal_bisect_right(a, key_x, lo, hi, key);
+        Py_DECREF(key_x);
+    }
     if (index < 0)
         return NULL;
     if (PyList_CheckExact(a)) {
@@ -117,7 +141,8 @@ _bisect_insort_right_impl(PyObject *module, PyObject *a, PyObject *x,
 }
 
 static inline Py_ssize_t
-internal_bisect_left(PyObject *list, PyObject *item, Py_ssize_t lo, Py_ssize_t hi)
+internal_bisect_left(PyObject *list, PyObject *item, Py_ssize_t lo, Py_ssize_t hi,
+                     PyObject *key)
 {
     PyObject *litem;
     Py_ssize_t mid;
@@ -140,6 +165,14 @@ internal_bisect_left(PyObject *list, PyObject *item, Py_ssize_t lo, Py_ssize_t h
         litem = PySequence_GetItem(list, mid);
         if (litem == NULL)
             return -1;
+        if (key != Py_None) {
+            PyObject *newitem = PyObject_CallOneArg(key, litem);
+            if (newitem == NULL) {
+                Py_DECREF(litem);
+                return -1;
+            }
+            Py_SETREF(litem, newitem);
+        }
         res = PyObject_RichCompareBool(litem, item, Py_LT);
         Py_DECREF(litem);
         if (res < 0)
@@ -160,6 +193,8 @@ _bisect.bisect_left -> Py_ssize_t
     x: object
     lo: Py_ssize_t = 0
     hi: Py_ssize_t(c_default='-1', accept={int, NoneType}) = None
+    *
+    key: object = None
 
 Return the index where to insert item x in list a, assuming a is sorted.
 
@@ -173,10 +208,10 @@ slice of a to be searched.
 
 static Py_ssize_t
 _bisect_bisect_left_impl(PyObject *module, PyObject *a, PyObject *x,
-                         Py_ssize_t lo, Py_ssize_t hi)
+                         Py_ssize_t lo, Py_ssize_t hi, PyObject *key)
-/*[clinic end generated code: output=af82168bc2856f24 input=2bd90f34afe5609f]*/
+/*[clinic end generated code: output=70749d6e5cae9284 input=3cbeec690f2f6c6e]*/
 {
-    return internal_bisect_left(a, x, lo, hi);
+    return internal_bisect_left(a, x, lo, hi, key);
 }
 
 
@@ -187,6 +222,8 @@ _bisect.insort_left
     x: object
     lo: Py_ssize_t = 0
     hi: Py_ssize_t(c_default='-1', accept={int, NoneType}) = None
+    *
+    key: object = None
 
 Insert item x in list a, and keep it sorted assuming a is sorted.
 
@@ -198,11 +235,22 @@ slice of a to be searched.
 
 static PyObject *
 _bisect_insort_left_impl(PyObject *module, PyObject *a, PyObject *x,
-                         Py_ssize_t lo, Py_ssize_t hi)
+                         Py_ssize_t lo, Py_ssize_t hi, PyObject *key)
-/*[clinic end generated code: output=9e8356c0844a182b input=bc4583308bce00cc]*/
+/*[clinic end generated code: output=b1d33e5e7ffff11e input=3ab65d8784f585b1]*/
 {
-    PyObject *result;
+    PyObject *result, *key_x;
-    Py_ssize_t index = internal_bisect_left(a, x, lo, hi);
+    Py_ssize_t index;
+    
+    if (key == Py_None) {
+        index = internal_bisect_left(a, x, lo, hi, key);
+    } else {
+        key_x = PyObject_CallOneArg(key, x);
+        if (x == NULL) {
+            return NULL;
+        }
+        index = internal_bisect_left(a, key_x, lo, hi, key);
+        Py_DECREF(key_x);
+    }
     if (index < 0)
         return NULL;
     if (PyList_CheckExact(a)) {

Modules/clinic/_bisectmodule.c.h

@@ -3,7 +3,7 @@ preserve
 [clinic start generated code]*/
 
 PyDoc_STRVAR(_bisect_bisect_right__doc__,
-"bisect_right($module, /, a, x, lo=0, hi=None)\n"
+"bisect_right($module, /, a, x, lo=0, hi=None, *, key=None)\n"
 "--\n"
 "\n"
 "Return the index where to insert item x in list a, assuming a is sorted.\n"
@@ -20,20 +20,21 @@ PyDoc_STRVAR(_bisect_bisect_right__doc__,
 
 static Py_ssize_t
 _bisect_bisect_right_impl(PyObject *module, PyObject *a, PyObject *x,
-                          Py_ssize_t lo, Py_ssize_t hi);
+                          Py_ssize_t lo, Py_ssize_t hi, PyObject *key);
 
 static PyObject *
 _bisect_bisect_right(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
 {
     PyObject *return_value = NULL;
-    static const char * const _keywords[] = {"a", "x", "lo", "hi", NULL};
+    static const char * const _keywords[] = {"a", "x", "lo", "hi", "key", NULL};
     static _PyArg_Parser _parser = {NULL, _keywords, "bisect_right", 0};
-    PyObject *argsbuf[4];
+    PyObject *argsbuf[5];
     Py_ssize_t noptargs = nargs + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 2;
     PyObject *a;
     PyObject *x;
     Py_ssize_t lo = 0;
     Py_ssize_t hi = -1;
+    PyObject *key = Py_None;
     Py_ssize_t _return_value;
 
     args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 2, 4, 0, argsbuf);
@@ -62,11 +63,21 @@ _bisect_bisect_right(PyObject *module, PyObject *const *args, Py_ssize_t nargs,
             goto skip_optional_pos;
         }
     }
-    if (!_Py_convert_optional_to_ssize_t(args[3], &hi)) {
+    if (args[3]) {
-        goto exit;
+        if (!_Py_convert_optional_to_ssize_t(args[3], &hi)) {
+            goto exit;
+        }
+        if (!--noptargs) {
+            goto skip_optional_pos;
+        }
     }
 skip_optional_pos:
-    _return_value = _bisect_bisect_right_impl(module, a, x, lo, hi);
+    if (!noptargs) {
+        goto skip_optional_kwonly;
+    }
+    key = args[4];
+skip_optional_kwonly:
+    _return_value = _bisect_bisect_right_impl(module, a, x, lo, hi, key);
     if ((_return_value == -1) && PyErr_Occurred()) {
         goto exit;
     }
@@ -77,7 +88,7 @@ exit:
 }
 
 PyDoc_STRVAR(_bisect_insort_right__doc__,
-"insort_right($module, /, a, x, lo=0, hi=None)\n"
+"insort_right($module, /, a, x, lo=0, hi=None, *, key=None)\n"
 "--\n"
 "\n"
 "Insert item x in list a, and keep it sorted assuming a is sorted.\n"
@@ -92,20 +103,21 @@ PyDoc_STRVAR(_bisect_insort_right__doc__,
 
 static PyObject *
 _bisect_insort_right_impl(PyObject *module, PyObject *a, PyObject *x,
-                          Py_ssize_t lo, Py_ssize_t hi);
+                          Py_ssize_t lo, Py_ssize_t hi, PyObject *key);
 
 static PyObject *
 _bisect_insort_right(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
 {
     PyObject *return_value = NULL;
-    static const char * const _keywords[] = {"a", "x", "lo", "hi", NULL};
+    static const char * const _keywords[] = {"a", "x", "lo", "hi", "key", NULL};
     static _PyArg_Parser _parser = {NULL, _keywords, "insort_right", 0};
-    PyObject *argsbuf[4];
+    PyObject *argsbuf[5];
     Py_ssize_t noptargs = nargs + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 2;
     PyObject *a;
     PyObject *x;
     Py_ssize_t lo = 0;
     Py_ssize_t hi = -1;
+    PyObject *key = Py_None;
 
     args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 2, 4, 0, argsbuf);
     if (!args) {
@@ -133,18 +145,28 @@ _bisect_insort_right(PyObject *module, PyObject *const *args, Py_ssize_t nargs,
             goto skip_optional_pos;
         }
     }
-    if (!_Py_convert_optional_to_ssize_t(args[3], &hi)) {
+    if (args[3]) {
-        goto exit;
+        if (!_Py_convert_optional_to_ssize_t(args[3], &hi)) {
+            goto exit;
+        }
+        if (!--noptargs) {
+            goto skip_optional_pos;
+        }
     }
 skip_optional_pos:
-    return_value = _bisect_insort_right_impl(module, a, x, lo, hi);
+    if (!noptargs) {
+        goto skip_optional_kwonly;
+    }
+    key = args[4];
+skip_optional_kwonly:
+    return_value = _bisect_insort_right_impl(module, a, x, lo, hi, key);
 
 exit:
     return return_value;
 }
 
 PyDoc_STRVAR(_bisect_bisect_left__doc__,
-"bisect_left($module, /, a, x, lo=0, hi=None)\n"
+"bisect_left($module, /, a, x, lo=0, hi=None, *, key=None)\n"
 "--\n"
 "\n"
 "Return the index where to insert item x in list a, assuming a is sorted.\n"
@@ -161,20 +183,21 @@ PyDoc_STRVAR(_bisect_bisect_left__doc__,
 
 static Py_ssize_t
 _bisect_bisect_left_impl(PyObject *module, PyObject *a, PyObject *x,
-                         Py_ssize_t lo, Py_ssize_t hi);
+                         Py_ssize_t lo, Py_ssize_t hi, PyObject *key);
 
 static PyObject *
 _bisect_bisect_left(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
 {
     PyObject *return_value = NULL;
-    static const char * const _keywords[] = {"a", "x", "lo", "hi", NULL};
+    static const char * const _keywords[] = {"a", "x", "lo", "hi", "key", NULL};
     static _PyArg_Parser _parser = {NULL, _keywords, "bisect_left", 0};
-    PyObject *argsbuf[4];
+    PyObject *argsbuf[5];
     Py_ssize_t noptargs = nargs + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 2;
     PyObject *a;
     PyObject *x;
     Py_ssize_t lo = 0;
     Py_ssize_t hi = -1;
+    PyObject *key = Py_None;
     Py_ssize_t _return_value;
 
     args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 2, 4, 0, argsbuf);
@@ -203,11 +226,21 @@ _bisect_bisect_left(PyObject *module, PyObject *const *args, Py_ssize_t nargs, P
             goto skip_optional_pos;
         }
     }
-    if (!_Py_convert_optional_to_ssize_t(args[3], &hi)) {
+    if (args[3]) {
-        goto exit;
+        if (!_Py_convert_optional_to_ssize_t(args[3], &hi)) {
+            goto exit;
+        }
+        if (!--noptargs) {
+            goto skip_optional_pos;
+        }
     }
 skip_optional_pos:
-    _return_value = _bisect_bisect_left_impl(module, a, x, lo, hi);
+    if (!noptargs) {
+        goto skip_optional_kwonly;
+    }
+    key = args[4];
+skip_optional_kwonly:
+    _return_value = _bisect_bisect_left_impl(module, a, x, lo, hi, key);
     if ((_return_value == -1) && PyErr_Occurred()) {
         goto exit;
     }
@@ -218,7 +251,7 @@ exit:
 }
 
 PyDoc_STRVAR(_bisect_insort_left__doc__,
-"insort_left($module, /, a, x, lo=0, hi=None)\n"
+"insort_left($module, /, a, x, lo=0, hi=None, *, key=None)\n"
 "--\n"
 "\n"
 "Insert item x in list a, and keep it sorted assuming a is sorted.\n"
@@ -233,20 +266,21 @@ PyDoc_STRVAR(_bisect_insort_left__doc__,
 
 static PyObject *
 _bisect_insort_left_impl(PyObject *module, PyObject *a, PyObject *x,
-                         Py_ssize_t lo, Py_ssize_t hi);
+                         Py_ssize_t lo, Py_ssize_t hi, PyObject *key);
 
 static PyObject *
 _bisect_insort_left(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
 {
     PyObject *return_value = NULL;
-    static const char * const _keywords[] = {"a", "x", "lo", "hi", NULL};
+    static const char * const _keywords[] = {"a", "x", "lo", "hi", "key", NULL};
     static _PyArg_Parser _parser = {NULL, _keywords, "insort_left", 0};
-    PyObject *argsbuf[4];
+    PyObject *argsbuf[5];
     Py_ssize_t noptargs = nargs + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 2;
     PyObject *a;
     PyObject *x;
     Py_ssize_t lo = 0;
     Py_ssize_t hi = -1;
+    PyObject *key = Py_None;
 
     args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 2, 4, 0, argsbuf);
     if (!args) {
@@ -274,13 +308,23 @@ _bisect_insort_left(PyObject *module, PyObject *const *args, Py_ssize_t nargs, P
             goto skip_optional_pos;
         }
     }
-    if (!_Py_convert_optional_to_ssize_t(args[3], &hi)) {
+    if (args[3]) {
-        goto exit;
+        if (!_Py_convert_optional_to_ssize_t(args[3], &hi)) {
+            goto exit;
+        }
+        if (!--noptargs) {
+            goto skip_optional_pos;
+        }
     }
 skip_optional_pos:
-    return_value = _bisect_insort_left_impl(module, a, x, lo, hi);
+    if (!noptargs) {
+        goto skip_optional_kwonly;
+    }
+    key = args[4];
+skip_optional_kwonly:
+    return_value = _bisect_insort_left_impl(module, a, x, lo, hi, key);
 
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=6cf46f205659f01a input=a9049054013a1b77]*/
+/*[clinic end generated code: output=b3a5be025aa4ed7e input=a9049054013a1b77]*/