diff --git a/Modules/grpmodule.c b/Modules/grpmodule.c
index 00d8af3b032..ef2f0f01412 100644
--- a/Modules/grpmodule.c
+++ b/Modules/grpmodule.c
@@ -15,97 +15,124 @@ redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 #include <sys/types.h>
 #include <grp.h>
 
-static PyObject *mkgrent(p)
-	struct group *p;
+
+static PyObject *
+mkgrent(struct group *p)
 {
-	PyObject *v, *w;
-	char **member;
-	if ((w = PyList_New(0)) == NULL) {
-		return NULL;
-	}
-	for (member = p->gr_mem; *member != NULL; member++) {
-		PyObject *x = PyString_FromString(*member);
-		if (x == NULL || PyList_Append(w, x) != 0) {
-			Py_XDECREF(x);
-			Py_DECREF(w);
-			return NULL;
-		}
-		Py_DECREF(x);
-	}
-	v = Py_BuildValue("(sslO)",
-		       p->gr_name,
-		       p->gr_passwd,
+    PyObject *v, *w;
+    char **member;
+    if ((w = PyList_New(0)) == NULL) {
+        return NULL;
+    }
+    for (member = p->gr_mem; *member != NULL; member++) {
+        PyObject *x = PyString_FromString(*member);
+        if (x == NULL || PyList_Append(w, x) != 0) {
+            Py_XDECREF(x);
+            Py_DECREF(w);
+            return NULL;
+        }
+        Py_DECREF(x);
+    }
+    v = Py_BuildValue("(sslO)",
+                      p->gr_name,
+                      p->gr_passwd,
 #if defined(NeXT) && defined(_POSIX_SOURCE) && defined(__LITTLE_ENDIAN__)
 /* Correct a bug present on Intel machines in NextStep 3.2 and 3.3;
    for later versions you may have to remove this */
-		       (long)p->gr_short_pad, /* ugh-NeXT broke the padding */
+                      (long)p->gr_short_pad, /* ugh-NeXT broke the padding */
 #else
-		       (long)p->gr_gid,
+                      (long)p->gr_gid,
 #endif
-		       w);
-	Py_DECREF(w);
-	return v;
+                      w);
+    Py_DECREF(w);
+    return v;
 }
 
-static PyObject *grp_getgrgid(self, args)
-	PyObject *self, *args;
+static PyObject *
+grp_getgrgid(PyObject *self, PyObject *args)
 {
-	int gid;
-	struct group *p;
-	if (!PyArg_Parse((args),"i",(&gid)))
-		return NULL;
-	if ((p = getgrgid(gid)) == NULL) {
-		PyErr_SetString(PyExc_KeyError, "getgrgid(): gid not found");
-		return NULL;
-	}
-	return mkgrent(p);
+    int gid;
+    struct group *p;
+    if (!PyArg_ParseTuple(args, "i:getgrgid", &gid))
+        return NULL;
+    if ((p = getgrgid(gid)) == NULL) {
+        PyErr_SetString(PyExc_KeyError, "getgrgid(): gid not found");
+        return NULL;
+    }
+    return mkgrent(p);
 }
 
-static PyObject *grp_getgrnam(self, args)
-	PyObject *self, *args;
+static PyObject *
+grp_getgrnam(PyObject *self, PyObject *args)
 {
-	char *name;
-	struct group *p;
-	if (!PyArg_Parse((args),"s",(&name)))
-		return NULL;
-	if ((p = getgrnam(name)) == NULL) {
-		PyErr_SetString(PyExc_KeyError, "getgrnam(): name not found");
-		return NULL;
-	}
-	return mkgrent(p);
+    char *name;
+    struct group *p;
+    if (!PyArg_ParseTuple(args, "s:getgrnam", &name))
+        return NULL;
+    if ((p = getgrnam(name)) == NULL) {
+        PyErr_SetString(PyExc_KeyError, "getgrnam(): name not found");
+        return NULL;
+    }
+    return mkgrent(p);
 }
 
-static PyObject *grp_getgrall(self, args)
-	PyObject *self, *args;
+static PyObject *
+grp_getgrall(PyObject *self, PyObject *args)
 {
-	PyObject *d;
-	struct group *p;
-	if (!PyArg_NoArgs(args))
-		return NULL;
-	if ((d = PyList_New(0)) == NULL)
-		return NULL;
-	setgrent();
-	while ((p = getgrent()) != NULL) {
-		PyObject *v = mkgrent(p);
-		if (v == NULL || PyList_Append(d, v) != 0) {
-			Py_XDECREF(v);
-			Py_DECREF(d);
-			return NULL;
-		}
-		Py_DECREF(v);
-	}
-	return d;
+    PyObject *d;
+    struct group *p;
+
+    if (!PyArg_ParseTuple(args, ":getgrall"))
+        return NULL;
+    if ((d = PyList_New(0)) == NULL)
+        return NULL;
+    setgrent();
+    while ((p = getgrent()) != NULL) {
+        PyObject *v = mkgrent(p);
+        if (v == NULL || PyList_Append(d, v) != 0) {
+            Py_XDECREF(v);
+            Py_DECREF(d);
+            return NULL;
+        }
+        Py_DECREF(v);
+    }
+    return d;
 }
 
 static PyMethodDef grp_methods[] = {
-	{"getgrgid",	grp_getgrgid},
-	{"getgrnam",	grp_getgrnam},
-	{"getgrall",	grp_getgrall},
-	{NULL,		NULL}		/* sentinel */
+    {"getgrgid",	grp_getgrgid,	METH_VARARGS,
+     "getgrgid(id) -> tuple\n\
+Return the group database entry for the given numeric group ID.  If\n\
+id is not valid, raise KeyError."},
+    {"getgrnam",	grp_getgrnam,	METH_VARARGS,
+     "getgrnam(name) -> tuple\n\
+Return the group database entry for the given group name.  If\n\
+name is not valid, raise KeyError."},
+    {"getgrall",	grp_getgrall,	METH_VARARGS,
+     "getgrall() -> list of tuples\n\
+Return a list of all available group entries, in arbitrary order."},
+    {NULL,		NULL}		/* sentinel */
 };
 
+static char grp__doc__[] =
+"Access to the Unix group database.\n\
+\n\
+Group entries are reported as 4-tuples containing the following fields\n\
+from the group database, in order:\n\
+\n\
+  name   - name of the group\n\
+  passwd - group password (encrypted); often empty\n\
+  gid    - numeric ID of the group\n\
+  mem    - list of members\n\
+\n\
+The gid is an integer, name and password are strings.  (Note that most\n\
+users are not explicitly listed as members of the groups they are in\n\
+according to the password database.  Check both databases to get\n\
+complete membership information.)";
+
+
 DL_EXPORT(void)
 initgrp()
 {
-	Py_InitModule("grp", grp_methods);
+    Py_InitModule3("grp", grp_methods, grp__doc__);
 }