From 6013bcb42506b9822c43dfe8e3dff5d2762c5185 Mon Sep 17 00:00:00 2001
From: Alireza Savand <alireza.savand@gmail.com>
Date: Thu, 22 Sep 2016 11:40:55 +0400
Subject: [PATCH 1/5] Fixes #4506: Support Python 3 annotations on fields
 callables

---
 rest_framework/fields.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/rest_framework/fields.py b/rest_framework/fields.py
index 917a151e5..7bf9ef1e3 100644
--- a/rest_framework/fields.py
+++ b/rest_framework/fields.py
@@ -59,7 +59,11 @@ def is_simple_callable(obj):
     if not (function or method):
         return False
 
-    args, _, _, defaults = inspect.getargspec(obj)
+    if six.PY2:
+        args, _, _, defaults = inspect.getargspec(obj)
+    else:
+        args, _, _, defaults = inspect.getfullargspec(obj)[:4]
+
     len_args = len(args) if function else len(args) - 1
     len_defaults = len(defaults) if defaults else 0
     return len_args <= len_defaults

From fe417aad79abc71d817b885ec6fd4e806d7fc38c Mon Sep 17 00:00:00 2001
From: Alireza Savand <alireza.savand@gmail.com>
Date: Thu, 22 Sep 2016 12:47:17 +0400
Subject: [PATCH 2/5] Add getargspec to compact

---
 rest_framework/compat.py | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/rest_framework/compat.py b/rest_framework/compat.py
index cee430a84..2f7961ca2 100644
--- a/rest_framework/compat.py
+++ b/rest_framework/compat.py
@@ -140,6 +140,16 @@ def value_from_object(field, obj):
     return field.value_from_object(obj)
 
 
+def getargspec(obj):  # type: tuple
+    if six.PY2:
+        parameters, _, _, defaults = inspect.getargspec(obj)
+    else:
+        signature = inspect.signature(obj)
+        parameters = signature.parameters
+        defaults = [i for i in parameters if i.default != inspect._empty]
+
+    return parameters, defaults
+
 # contrib.postgres only supported from 1.8 onwards.
 try:
     from django.contrib.postgres import fields as postgres_fields

From 974b94dfd7a0e7db38967e8863c1a7b59b279591 Mon Sep 17 00:00:00 2001
From: Alireza Savand <alireza.savand@gmail.com>
Date: Thu, 22 Sep 2016 12:47:31 +0400
Subject: [PATCH 3/5] Using getargspec from compat

---
 rest_framework/fields.py | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/rest_framework/fields.py b/rest_framework/fields.py
index 7bf9ef1e3..835739612 100644
--- a/rest_framework/fields.py
+++ b/rest_framework/fields.py
@@ -32,7 +32,8 @@ from django.utils.translation import ugettext_lazy as _
 
 from rest_framework import ISO_8601
 from rest_framework.compat import (
-    get_remote_field, unicode_repr, unicode_to_repr, value_from_object
+    get_remote_field, getargspec, unicode_repr, unicode_to_repr,
+    value_from_object
 )
 from rest_framework.exceptions import ValidationError
 from rest_framework.settings import api_settings
@@ -59,12 +60,9 @@ def is_simple_callable(obj):
     if not (function or method):
         return False
 
-    if six.PY2:
-        args, _, _, defaults = inspect.getargspec(obj)
-    else:
-        args, _, _, defaults = inspect.getfullargspec(obj)[:4]
+    parameters, defaults = getargspec(obj)
 
-    len_args = len(args) if function else len(args) - 1
+    len_args = len(parameters) if function else len(parameters) - 1
     len_defaults = len(defaults) if defaults else 0
     return len_args <= len_defaults
 

From 610e8ca75ca9ad8fd70c88a4785965cd5e0fd5dd Mon Sep 17 00:00:00 2001
From: Alireza Savand <alireza.savand@gmail.com>
Date: Thu, 22 Sep 2016 13:10:02 +0400
Subject: [PATCH 4/5] Better to check of existence of `signature`

---
 rest_framework/compat.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rest_framework/compat.py b/rest_framework/compat.py
index 2f7961ca2..c278448fd 100644
--- a/rest_framework/compat.py
+++ b/rest_framework/compat.py
@@ -141,7 +141,7 @@ def value_from_object(field, obj):
 
 
 def getargspec(obj):  # type: tuple
-    if six.PY2:
+    if not hasattr(inspect, 'signature'):
         parameters, _, _, defaults = inspect.getargspec(obj)
     else:
         signature = inspect.signature(obj)

From 14c22bcab383eec424e32c05ea6df37ba88993b9 Mon Sep 17 00:00:00 2001
From: Alireza Savand <alireza.savand@gmail.com>
Date: Thu, 22 Sep 2016 14:29:36 +0400
Subject: [PATCH 5/5] Coment t o show whihc python version is statement for

---
 rest_framework/compat.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/rest_framework/compat.py b/rest_framework/compat.py
index c278448fd..8fc7f8a53 100644
--- a/rest_framework/compat.py
+++ b/rest_framework/compat.py
@@ -140,10 +140,10 @@ def value_from_object(field, obj):
     return field.value_from_object(obj)
 
 
-def getargspec(obj):  # type: tuple
-    if not hasattr(inspect, 'signature'):
+def getargspec(obj):
+    if not hasattr(inspect, 'signature'):  # Python 2.7 - 3.2
         parameters, _, _, defaults = inspect.getargspec(obj)
-    else:
+    else:  # Python +3.3
         signature = inspect.signature(obj)
         parameters = signature.parameters
         defaults = [i for i in parameters if i.default != inspect._empty]