From 4733eb333abca8c38736fd4e0b391aa86900f660 Mon Sep 17 00:00:00 2001
From: Pieter Marsman <pietermarsman@gmail.com>
Date: Sun, 26 Jun 2022 17:47:28 +0200
Subject: [PATCH] Install typing_extensions on Python 3.6 and 3.7 (#775)

* Install typing_extensions on Python 3.6 and 3.7

* Add CHANGELOG.md

* Black setup.py
---
 CHANGELOG.md      | 1 +
 pdfminer/image.py | 1 +
 setup.py          | 1 +
 3 files changed, 3 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 84a0c5d..dc3ec73 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - `ValueError` when trying to decrypt empty metadata values ([#766](https://github.com/pdfminer/pdfminer.six/issues/766))
 - Sphinx errors during building of documentation ([#760](https://github.com/pdfminer/pdfminer.six/pull/760))
 - `TypeError` when getting default width of font ([#720](https://github.com/pdfminer/pdfminer.six/issues/720))
+- Install typing-extensions on Python 3.6 and 3.7 ([#775](https://github.com/pdfminer/pdfminer.six/pull/775))
 - `TypeError` in cmapdb.py when parsing null characters ([#768](https://github.com/pdfminer/pdfminer.six/pull/768))
 
 ### Deprecated
diff --git a/pdfminer/image.py b/pdfminer/image.py
index 2b41253..54b1492 100644
--- a/pdfminer/image.py
+++ b/pdfminer/image.py
@@ -7,6 +7,7 @@ from typing import BinaryIO, Tuple
 try:
     from typing import Literal
 except ImportError:
+    # Literal was introduced in Python 3.8
     from typing_extensions import Literal  # type: ignore[misc]
 
 from .jbig2 import JBIG2StreamReader, JBIG2StreamWriter
diff --git a/setup.py b/setup.py
index 0196b48..2bcba0b 100644
--- a/setup.py
+++ b/setup.py
@@ -19,6 +19,7 @@ setup(
     install_requires=[
         "charset-normalizer >= 2.0.0",
         "cryptography >= 36.0.0",
+        'typing_extensions; python_version < "3.8"',
     ],
     extras_require={
         "dev": ["pytest", "nox", "black", "mypy == 0.931"],