Issue #14783: Backport changes from 3.2.

Objects/intobject.c

@@ -1334,15 +1334,20 @@ static PyGetSetDef int_getset[] = {
 };
 
 PyDoc_STRVAR(int_doc,
-"int(x[, base]) -> integer\n\
+"int(x=0) -> int or long\n\
+int(x, base=10) -> int or long\n\
 \n\
-Convert a string or number to an integer, if possible.  A floating point\n\
-argument will be truncated towards zero (this does not include a string\n\
-representation of a floating point number!)  When converting a string, use\n\
-the optional base.  It is an error to supply a base when converting a\n\
-non-string.  If base is zero, the proper base is guessed based on the\n\
-string content.  If the argument is outside the integer range a\n\
-long object will be returned instead.");
+Convert a number or string to an integer, or return 0 if no arguments\n\
+are given.  If x is floating point, the conversion truncates towards zero.\n\
+If x is outside the integer range, the function returns a long instead.\n\
+\n\
+If x is not a number or if base is given, then x must be a string or\n\
+Unicode object representing an integer literal in the given base.  The\n\
+literal can be preceded by '+' or '-' and be surrounded by whitespace.\n\
+The base defaults to 10.  Valid bases are 0 and 2-36.  Base 0 means to\n\
+interpret the base from the string as an integer literal.\n\
+>>> int('0b100', base=0)\n\
+4");
 
 static PyNumberMethods int_as_number = {
     (binaryfunc)int_add,        /*nb_add*/

Objects/longobject.c

@@ -4221,13 +4221,19 @@ static PyGetSetDef long_getset[] = {
 };
 
 PyDoc_STRVAR(long_doc,
-"long(x[, base]) -> integer\n\
+"long(x=0) -> long\n\
+long(x, base=10) -> long\n\
 \n\
-Convert a string or number to a long integer, if possible.  A floating\n\
-point argument will be truncated towards zero (this does not include a\n\
-string representation of a floating point number!)  When converting a\n\
-string, use the optional base.  It is an error to supply a base when\n\
-converting a non-string.");
+Convert a number or string to a long integer, or return 0L if no arguments\n\
+are given.  If x is floating point, the conversion truncates towards zero.\n\
+\n\
+If x is not a number or if base is given, then x must be a string or\n\
+Unicode object representing an integer literal in the given base.  The\n\
+literal can be preceded by '+' or '-' and be surrounded by whitespace.\n\
+The base defaults to 10.  Valid bases are 0 and 2-36.  Base 0 means to\n\
+interpret the base from the string as an integer literal.\n\
+>>> int('0b100', base=0)\n\
+4L");
 
 static PyNumberMethods long_as_number = {
     (binaryfunc)long_add,       /*nb_add*/

Objects/rangeobject.c

@@ -104,7 +104,8 @@ range_new(PyTypeObject *type, PyObject *args, PyObject *kw)
 }
 
 PyDoc_STRVAR(range_doc,
-"xrange([start,] stop[, step]) -> xrange object\n\
+"xrange(stop) -> xrange object\n\
+xrange(start, stop[, step]) -> xrange object\n\
 \n\
 Like range(), but instead of returning a list, returns an object that\n\
 generates the numbers in the range on demand.  For looping, this is \n\

Objects/sliceobject.c

@@ -211,7 +211,8 @@ slice_new(PyTypeObject *type, PyObject *args, PyObject *kw)
 }
 
 PyDoc_STRVAR(slice_doc,
-"slice([start,] stop[, step])\n\
+"slice(stop)\n\
+slice(start, stop[, step])\n\
 \n\
 Create a slice object.  This is used for extended slicing (e.g. a[0:10:2]).");
 

Objects/stringobject.c

@@ -3799,7 +3799,7 @@ PyTypeObject PyBaseString_Type = {
 };
 
 PyDoc_STRVAR(string_doc,
-"str(object) -> string\n\
+"str(object='') -> string\n\
 \n\
 Return a nice string representation of the object.\n\
 If the argument is a string, the return value is the same object.");

Objects/unicodeobject.c

@@ -1861,7 +1861,7 @@ char utf8_code_length[256] = {
        illegal prefix.  See RFC 3629 for details */
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 00-0F */
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
@@ -2217,7 +2217,7 @@ PyUnicode_DecodeUTF32Stateful(const char *s,
 #endif
     PyObject *errorHandler = NULL;
     PyObject *exc = NULL;
-    
+
     q = (unsigned char *)s;
     e = q + size;
 
@@ -8759,7 +8759,8 @@ unicode_subtype_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
 }
 
 PyDoc_STRVAR(unicode_doc,
-             "unicode(string [, encoding[, errors]]) -> object\n\
+             "unicode(object='') -> unicode object\n\
+unicode(string[, encoding[, errors]]) -> unicode object\n\
 \n\
 Create a new Unicode object from the given encoded string.\n\
 encoding defaults to the current default string encoding.\n\