Separate the handling of third party and first party imports

ChangeLog

@@ -146,6 +146,10 @@ What's New in Pylint 1.8?
       deeply nested inside loop.
       Close #1661
+    * Fix no ``wrong-import-order`` message emitted on ordering of first and third party
+      libraries. With this fix, pylint distinguishes third and first party
+      modules when checking import order.
+      Close #1702
 What's New in Pylint 1.7.1?
 =========================

doc/whatsnew/1.8.rst

@@ -351,5 +351,9 @@ Other Changes
 * The Python 3 porting checker respects disabled checkers found in the config file.
- * Modules, classes, or methods consist of compound statements that exceed the ``docstring-min-length``
-   are now correctly emitting `missing-docstring`
+* Modules, classes, or methods consist of compound statements that exceed the ``docstring-min-length``
+  are now correctly emitting `missing-docstring`
+
+* Fix no ``wrong-import-order`` message emitted on ordering of first and third party libraries.
+  With this fix, pylint distinguishes first and third party modules when checking
+  import order.

pylint/checkers/imports.py

+# -*- coding: utf-8 -*-
 # Copyright (c) 2006-2015 LOGILAB S.A. (Paris, FRANCE) <contact@logilab.fr>
 # Copyright (c) 2012-2014 Google, Inc.
 # Copyright (c) 2014-2016 Claudiu Popa <pcmanticore@gmail.com>
@@ -563,10 +564,14 @@ class ImportsChecker(BaseChecker):
         Imports must follow this order: standard, 3rd party, local
         """
-        extern_imports = []
-        local_imports = []
         std_imports = []
-        extern_not_ignored = []
+        third_party_imports = []
+        first_party_imports = []
+        # need of a list that holds third or first party ordered import
+        external_imports = []
+        local_imports = []
+        third_party_not_ignored = []
+        first_party_not_ignored = []
         local_not_ignored = []
         isort_obj = isort.SortImports(
             file_contents='', known_third_party=self.config.known_third_party,
@@ -581,29 +586,42 @@ class ImportsChecker(BaseChecker):
             ignore_for_import_order = not self.linter.is_message_enabled('wrong-import-order',
                                                                          node.fromlineno)
             import_category = isort_obj.place_module(package)
+            node_and_package_import = (node, package)
             if import_category in ('FUTURE', 'STDLIB'):
-                std_imports.append((node, package))
-                wrong_import = extern_not_ignored or local_not_ignored
+                std_imports.append(node_and_package_import)
+                wrong_import = (third_party_not_ignored or first_party_not_ignored
+                                or local_not_ignored)
                 if self._is_fallback_import(node, wrong_import):
                     continue
                 if wrong_import and not nested:
                     self.add_message('wrong-import-order', node=node,
                                      args=('standard import "%s"' % node.as_string(),
                                            '"%s"' % wrong_import[0][0].as_string()))
-            elif import_category in ('FIRSTPARTY', 'THIRDPARTY'):
-                extern_imports.append((node, package))
+            elif import_category == 'THIRDPARTY':
+                third_party_imports.append(node_and_package_import)
+                external_imports.append(node_and_package_import)
+                if not nested and not ignore_for_import_order:
+                    third_party_not_ignored.append(node_and_package_import)
+                wrong_import = first_party_not_ignored or local_not_ignored
+                if wrong_import and not nested:
+                    self.add_message('wrong-import-order', node=node,
+                                     args=('third party import "%s"' % node.as_string(),
+                                           '"%s"' % wrong_import[0][0].as_string()))
+            elif import_category == 'FIRSTPARTY':
+                first_party_imports.append(node_and_package_import)
+                external_imports.append(node_and_package_import)
                 if not nested and not ignore_for_import_order:
-                    extern_not_ignored.append((node, package))
+                    first_party_not_ignored.append(node_and_package_import)
                 wrong_import = local_not_ignored
                 if wrong_import and not nested:
                     self.add_message('wrong-import-order', node=node,
-                                     args=('external import "%s"' % node.as_string(),
+                                     args=('first party import "%s"' % node.as_string(),
                                            '"%s"' % wrong_import[0][0].as_string()))
             elif import_category == 'LOCALFOLDER':
                 local_imports.append((node, package))
                 if not nested and not ignore_for_import_order:
                     local_not_ignored.append((node, package))
-        return std_imports, extern_imports, local_imports
+        return std_imports, external_imports, local_imports
     def _get_imported_module(self, importnode, modname):
         try:

pylint/test/functional/wrong_import_order.py

 """Checks import order rule"""
 # pylint: disable=unused-import,relative-import,ungrouped-imports,import-error,no-name-in-module,relative-beyond-top-level
+from __future__ import absolute_import
 try:
     from six.moves import configparser
 except ImportError:

pylint/test/functional/wrong_import_order.txt

-wrong-import-order:11::standard import "import os.path" should be placed before "import six"
-wrong-import-order:13::standard import "import sys" should be placed before "import six"
-wrong-import-order:14::standard import "import datetime" should be placed before "import six"
-wrong-import-order:17::external import "import totally_missing" should be placed before "from .package import Class"
-wrong-import-order:19::external import "import astroid" should be placed before "from .package import Class"
+wrong-import-order:12::standard import "import os.path" should be placed before "import six"
+wrong-import-order:14::standard import "import sys" should be placed before "import six"
+wrong-import-order:15::standard import "import datetime" should be placed before "import six"
+wrong-import-order:18::first party import "import totally_missing" should be placed before "from .package import Class"
+wrong-import-order:20::third party import "import astroid" should be placed before "import unused_import"

pylint/test/functional/wrong_import_order2.py

@@ -7,7 +7,7 @@ import os
 from sys import argv
 # external imports
-import lxml
+import isort
 from six import moves