From 917049816759be44b79aa48436bb1480366a4f7b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hakan=20=C3=87elik?= <hakancelik96@outlook.com>
Date: Wed, 7 Oct 2020 22:11:53 +0300
Subject: [PATCH] =?UTF-8?q?=F0=9F=90=9E=20Fix:=20Initial=20imports=20from?=
 =?UTF-8?q?=20sys.modules=20#127=20(#136)?=
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---
 docs/CHANGELOG.md      |  1 +
 tests/test_refactor.py | 12 ++++++++++++
 unimport/constants.py  | 17 +++++++++++++++++
 unimport/scan.py       |  8 +++++++-
 4 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 3629782e..526db59a 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -4,6 +4,7 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased] - ././2020
 
+- [🐞 Fix: Initial imports from sys.modules by @hakancelik96](https://github.com/hakancelik96/unimport/pull/136)
 - [🐞 Fix: import and name matcher by @hakancelik96](https://github.com/hakancelik96/unimport/pull/133)
 - [🐞 Fix: type comment by @hakancelik96](https://github.com/hakancelik96/unimport/pull/130)
 - [💪 Support type variable by @hakancelik96](https://github.com/hakancelik96/unimport/pull/128)
diff --git a/tests/test_refactor.py b/tests/test_refactor.py
index 9f51c055..e18dcf4f 100644
--- a/tests/test_refactor.py
+++ b/tests/test_refactor.py
@@ -242,6 +242,18 @@ def test_get_star_imp_none(self):
             self.session.refactor(action),
         )
 
+    def test_initial_imports(self):
+        from unimport.constants import INITIAL_IMPORTS
+
+        actions = [
+            (f"import {imp_name}\n{imp_name.split('.')[0]}\n")
+            for imp_name in INITIAL_IMPORTS
+        ]
+        self.assertListEqual(
+            actions,
+            [self.session.refactor(action) for action in actions],
+        )
+
 
 class TestDuplicateUnusedRefactor(RefactorTestCase):
     def test_full_unused(self):
diff --git a/unimport/constants.py b/unimport/constants.py
index f3e90230..150065a6 100644
--- a/unimport/constants.py
+++ b/unimport/constants.py
@@ -56,3 +56,20 @@
     SUBSCRIPT_TYPE_VARIABLE.extend(["Literal", "OrderedDict"])
 elif PY37_PLUS:
     SUBSCRIPT_TYPE_VARIABLE.append("Literal")
+
+INITIAL_IMPORTS = frozenset(
+    # https://docs.python.org/3/library/sys.html#sys.modules
+    # The first thing Python will do is look up the name of import in sys.modules.
+    # Initial modules are below.
+    {
+        "encodings.utf_8",
+        "encodings.aliases",
+        "encodings.latin_1",
+        "importlib._bootstrap",
+        "importlib.abc",
+        "importlib.machinery",
+        "importlib._bootstrap_external",
+        "importlib.util",
+        "os.path",
+    }
+)
diff --git a/unimport/scan.py b/unimport/scan.py
index 5af91c70..b6cc78a2 100644
--- a/unimport/scan.py
+++ b/unimport/scan.py
@@ -17,7 +17,11 @@
 )
 
 from unimport import color
-from unimport.constants import PY38_PLUS, SUBSCRIPT_TYPE_VARIABLE
+from unimport.constants import (
+    INITIAL_IMPORTS,
+    PY38_PLUS,
+    SUBSCRIPT_TYPE_VARIABLE,
+)
 from unimport.relate import first_occurrence, get_parents, relate
 from unimport.statement import Import, ImportFrom, Name
 from unimport.utils import get_dir, get_source, is_std
@@ -103,6 +107,8 @@ def visit_Import(self, node: ast.Import) -> None:
             return
         for column, alias in enumerate(node.names):
             name = alias.asname or alias.name
+            if name in INITIAL_IMPORTS:
+                name = name.split(".")[0]
             self.imports.append(
                 Import(
                     lineno=node.lineno,