Bump required Python version to 3.8 in remaining places.

Follow up to 38d48aa.

CONTRIBUTING.md

@@ -30,7 +30,7 @@ Any contribution is appreciated! You might want to:
 * Pull requests should be merged to master.
 * Include unit tests when possible. In case of bugs, this will help to prevent the same mistake in the future. In case
   of features, this will show that your code works correctly.
-* Code should work for Python 3.6+.
+* Code should work for Python 3.8+.
 * Test your code by using nox (see below). 
 * New features should be well documented using docstrings.
 * Check if the [README.md](../README.md) or [readthedocs](../docs/source) documentation needs to be updated. 

docs/source/index.rst

@@ -59,7 +59,7 @@ Features
 Installation instructions
 =========================
 
-* Install Python 3.6 or newer.
+* Install Python 3.8 or newer.
 * Install pdfminer.six.
 
 ::

pdfminer/pdftypes.py

@@ -1,13 +1,13 @@
 import io
 import logging
-import sys
 import zlib
 from typing import (
     TYPE_CHECKING,
     Any,
     Dict,
     Iterable,
     Optional,
+    Protocol,
     Union,
     List,
     Tuple,
@@ -44,25 +44,17 @@
 LITERALS_JPX_DECODE = (LIT("JPXDecode"),)
 
 
-if sys.version_info >= (3, 8):
-    from typing import Protocol
+class DecipherCallable(Protocol):
+    """Fully typed a decipher callback, with optional parameter."""
 
-    class DecipherCallable(Protocol):
-        """Fully typed a decipher callback, with optional parameter."""
-
-        def __call__(
-            self,
-            objid: int,
-            genno: int,
-            data: bytes,
-            attrs: Optional[Dict[str, Any]] = None,
-        ) -> bytes:
-            raise NotImplementedError
-
-else:  # Fallback for older Python
-    from typing import Callable
-
-    DecipherCallable = Callable[..., bytes]
+    def __call__(
+        self,
+        objid: int,
+        genno: int,
+        data: bytes,
+        attrs: Optional[Dict[str, Any]] = None,
+    ) -> bytes:
+        raise NotImplementedError
 
 
 class PDFObject(PSObject):

pdfminer/utils.py

@@ -39,7 +39,7 @@
 AnyIO = Union[TextIO, BinaryIO]
 
 
-class open_filename(object):
+class open_filename:
     """
     Context manager that allows opening a filename
     (str or pathlib.PurePath type is supported) and closes it on exit,

setup.py

@@ -16,8 +16,6 @@
     install_requires=[
         "charset-normalizer >= 2.0.0",
         "cryptography >= 36.0.0",
-        'typing_extensions; python_version < "3.8"',
-        'importlib_metadata; python_version < "3.8"',
     ],
     extras_require={
         "dev": ["pytest", "nox", "black", "mypy == 0.931"],
@@ -41,7 +39,7 @@
         "layout analysis",
         "text mining",
     ],
-    python_requires=">=3.6",
+    python_requires=">=3.8",
     classifiers=[
         "Programming Language :: Python",
         "Programming Language :: Python :: 3.8",

tests/test_pdfdocument.py

@@ -8,7 +8,7 @@
 from tests.helpers import absolute_sample_path
 
 
-class TestPdfDocument(object):
+class TestPdfDocument:
     def test_get_zero_objid_raises_pdfobjectnotfound(self):
         with open(absolute_sample_path("simple1.pdf"), "rb") as in_file:
             parser = PDFParser(in_file)

tests/test_pdfpage.py

@@ -4,7 +4,7 @@
 from tests.helpers import absolute_sample_path
 
 
-class TestPdfPage(object):
+class TestPdfPage:
     def test_page_labels(self):
         path = absolute_sample_path("contrib/pagelabels.pdf")
         expected_labels = ["iii", "iv", "1", "2", "1"]

tests/test_utils.py

@@ -71,7 +71,7 @@ def given_plane_with_one_object(object_size=50, gridsize=50):
         return plane, obj
 
 
-class TestFunctions(object):
+class TestFunctions:
     def test_shorten_str(self):
         s = shorten_str("Hello there World", 15)
         assert s == "Hello ... World"