Correct occurance → occurrence; extracted from patch by Georg Brandl
diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c
index f13bc14..9e3cead 100644
--- a/Objects/bytearrayobject.c
+++ b/Objects/bytearrayobject.c
@@ -1990,7 +1990,7 @@
     }
 
     if (to_len == 0) {
-        /* delete all occurances of 'from' bytes */
+        /* delete all occurrences of 'from' bytes */
         if (from_len == 1) {
             return replace_delete_single_character(
                     self, from_s[0], maxcount);
@@ -2399,7 +2399,7 @@
 PyDoc_STRVAR(remove__doc__,
 "B.remove(int) -> None\n\
 \n\
-Remove the first occurance of a value in B.");
+Remove the first occurrence of a value in B.");
 static PyObject *
 bytearray_remove(PyByteArrayObject *self, PyObject *arg)
 {
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 4e5d917..aa88152 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -2775,7 +2775,7 @@
     }
 
     if (to_len == 0) {
-        /* delete all occurances of 'from' string */
+        /* delete all occurrences of 'from' string */
         if (from_len == 1) {
             return replace_delete_single_character(
                 self, from_s[0], maxcount);