Remove Python 2.7 compatibility.

It is no longer support on GitHub actions anymore,
so it is time to give up on it.

Signed-off-by: Chris Lalancette <clalancette@gmail.com>

Author: clalancette

Makefile

@@ -41,7 +41,6 @@ sdist:
 	python3 setup.py sdist
 
 slowtests:
-	-PYCDLIB_TRACK_WRITES=1 [ -x /usr/bin/py.test-2 ] && py.test-2 --basetemp=/var/tmp/pycdlib-tests --runslow --verbose tests
 	PYCDLIB_TRACK_WRITES=1 py.test-3 --basetemp=/var/tmp/pycdlib-tests --runslow --verbose tests
 
 srpm: sdist
@@ -53,7 +52,6 @@ test-coverage:
 	xdg-open htmlcov/index.html
 
 tests:
-	-[ -x /usr/bin/py.test-2 ] && py.test-2 --verbose tests
 	py.test-3 --verbose tests
 
 .PHONY: clean deb docs flake8 lineprof mypy profile pylint rpm sdist slowtests srpm test-coverage tests

docs/design.md

@@ -12,7 +12,6 @@ The original motivation for writing the library was to replace the subprocess ca
 * Support for all of the common optical disk filesystems and their extensions.
 * Compatibility with the large corpus of existing ISOs (this implies reading ISOs that violate the standards).
 * Relatively simple API.
-* Python 2 and Python 3 compatibility.
 * Expansive test coverage.
 * In-place modification of existing ISOs, something that none of the other libraries support.
 * Performance approaching that of genisoimage.

docs/python-compatibility.md

@@ -1,5 +1,5 @@
 # Python Compatibility
-PyCdlib works equally well with Python 2.7 and Python 3.4+.  The [test suite](design.md#testing) ensures that the core PyCdlib code works with both flavors of Python.  Note that all of the command-line tools use Python 3 by default.
+The [test suite](design.md#testing) ensures that the core PyCdlib code works with all versions of Python greater than or equal to Python 3.7.
 
 ---
 

pycdlib/backport_functools.py

@@ -18,20 +18,15 @@
 Classes and utilities for ISO date support.
 """
 
-from __future__ import absolute_import
-
+import functools
 import struct
 import time
-try:
-    from functools import lru_cache
-except ImportError:
-    from pycdlib.backport_functools import lru_cache  # type: ignore
 
 from pycdlib import pycdlibexception
 from pycdlib import utils
 
 
-@lru_cache(maxsize=256)
+@functools.lru_cache(maxsize=256)
 def string_to_timestruct(input_string):
     # type: (bytes) -> time.struct_time
     """
@@ -59,7 +54,7 @@ def string_to_timestruct(input_string):
     return timestruct
 
 
-class DirectoryRecordDate(object):
+class DirectoryRecordDate:
     """
     A class to represent a Directory Record date as described in Ecma-119
     section 9.1.5.  The Directory Record date consists of the number of years
@@ -147,7 +142,7 @@ def __ne__(self, other):
             self.second != other.second or self.gmtoffset != other.gmtoffset
 
 
-class VolumeDescriptorDate(object):
+class VolumeDescriptorDate:
     """
     A class to represent a Volume Descriptor Date as described in Ecma-119
     section 8.4.26.1.  The Volume Descriptor Date consists of a year (from 1 to

pycdlib/dates.py

@@ -18,8 +18,6 @@
 The class to support ISO9660 Directory Records.
 """
 
-from __future__ import absolute_import
-
 import bisect
 import struct
 
@@ -31,13 +29,13 @@
 
 # For mypy annotations
 if False:  # pylint: disable=using-constant-test
-    from typing import BinaryIO, List, Optional, Tuple, Union  # NOQA pylint: disable=unused-import
+    from typing import Any, IO, List, Optional, Tuple, Union  # NOQA pylint: disable=unused-import
     # NOTE: these imports have to be here to avoid circular deps
     from pycdlib import headervd  # NOQA pylint: disable=unused-import
     from pycdlib import path_table_record  # NOQA pylint: disable=unused-import
 
 
-class XARecord(object):
+class XARecord:
     """
     A class that represents an ISO9660 Extended Attribute record as defined
     in the Philips Yellow Book standard.
@@ -149,7 +147,7 @@ def length():
         return 14
 
 
-class DirectoryRecord(object):
+class DirectoryRecord:
     """A class that represents an ISO9660 directory record."""
     __slots__ = ('initialized', 'new_extent_loc', 'ptr', 'extents_to_here',
                  'offset_to_here', 'data_continuation', 'vd', 'children',
@@ -1190,7 +1188,7 @@ def set_data_length(self, length):
 
     @property
     def data_fp(self):
-        # type: () -> Optional[Union[BinaryIO, str]]
+        # type: () -> Optional[Union[IO[Any], str]]
         """Backwards compatibility property for 'data_fp'."""
         if self.inode is None:
             return None

pycdlib/dr.py

@@ -16,9 +16,6 @@
 
 """Classes to support El Torito."""
 
-from __future__ import absolute_import
-from __future__ import print_function
-
 import logging
 import struct
 
@@ -38,7 +35,7 @@
 _logger = logging.getLogger('pycdlib')
 
 
-class EltoritoBootInfoTable(object):
+class EltoritoBootInfoTable:
     """
     A class that represents an El Torito Boot Info Table.  The Boot Info Table
     is an optional table that may be patched into the boot file at offset 8,
@@ -132,7 +129,7 @@ def header_length():
         return 16
 
 
-class EltoritoValidationEntry(object):
+class EltoritoValidationEntry:
     """
     A class that represents an El Torito Validation Entry.  El Torito requires
     that the first entry in the El Torito Boot Catalog be a validation entry.
@@ -277,7 +274,7 @@ def record(self):
         return self._record()
 
 
-class EltoritoEntry(object):
+class EltoritoEntry:
     """A class that represents an El Torito Entry (Initial or Section)."""
     __slots__ = ('_initialized', 'inode', 'boot_indicator',
                  'boot_media_type', 'load_segment', 'system_type',
@@ -493,7 +490,7 @@ def set_data_length(self, length):
         self.sector_count = utils.ceiling_div(length, 512)
 
 
-class EltoritoSectionHeader(object):
+class EltoritoSectionHeader:
     """A class that represents an El Torito Section Header."""
     __slots__ = ('_initialized', 'header_indicator', 'platform_id',
                  'num_section_entries', 'id_string', 'section_entries')
@@ -621,7 +618,7 @@ def record(self):
         return b''.join(outlist)
 
 
-class EltoritoBootCatalog(object):
+class EltoritoBootCatalog:
     """
     A class that represents an El Torito Boot Catalog.  The boot catalog is the
     basic unit of El Torito, and is expected to contain a validation entry,