From c7bce44745a20cc9856d8594fa619a8a715d4e90 Mon Sep 17 00:00:00 2001
From: Karthikeyan Singaravelan <tir.karthi@gmail.com>
Date: Wed, 22 Jan 2020 23:15:20 +0530
Subject: [PATCH 1/2] Import ABC from collections.abc instead of collections
 for Python 3.9 compatibility.

---
 bitstring.py           | 12 ++++++++----
 test/test_bitstream.py |  9 +++++++--
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/bitstring.py b/bitstring.py
index e3ea1590..14c93881 100644
--- a/bitstring.py
+++ b/bitstring.py
@@ -72,9 +72,13 @@
 import os
 import struct
 import operator
-import collections
 import array
 
+try:
+    from collections.abc import Iterable
+except ImportError:
+    from collections import Iterable
+
 byteorder = sys.byteorder
 
 bytealigned = False
@@ -1311,7 +1315,7 @@ def _setauto(self, s, length, offset):
             data = bytearray((s + 7) // 8)
             self._datastore = ByteStore(data, s, 0)
             return
-        if isinstance(s, collections.Iterable):
+        if isinstance(s, Iterable):
             # Evaluate each item as True or False and set bits to 1 or 0.
             self._setbin_unsafe(''.join(str(int(bool(x))) for x in s))
             return
@@ -3501,7 +3505,7 @@ def invert(self, pos=None):
         if pos is None:
             self._invert_all()
             return
-        if not isinstance(pos, collections.Iterable):
+        if not isinstance(pos, Iterable):
             pos = (pos,)
         length = self.len
 
@@ -3589,7 +3593,7 @@ def byteswap(self, fmt=None, start=None, end=None, repeat=True):
                     bytesizes.append(PACK_CODE_SIZE[f])
                 else:
                     bytesizes.extend([PACK_CODE_SIZE[f[-1]]] * int(f[:-1]))
-        elif isinstance(fmt, collections.Iterable):
+        elif isinstance(fmt, Iterable):
             bytesizes = fmt
             for bytesize in bytesizes:
                 if not isinstance(bytesize, numbers.Integral) or bytesize < 0:
diff --git a/test/test_bitstream.py b/test/test_bitstream.py
index 1a91d37d..3c4f286b 100644
--- a/test/test_bitstream.py
+++ b/test/test_bitstream.py
@@ -6,7 +6,12 @@
 import bitstring
 import copy
 import os
-import collections
+
+try:
+    from collections.abc import Iterable
+except ImportError:
+    from collections import Iterable
+
 from bitstring import BitStream, ConstBitStream, pack
 from bitstring import offsetcopy
 
@@ -3457,7 +3462,7 @@ def testPackingDefaultIntWithKeyword(self):
         self.assertEqual(s.len, 17)
 
     def testInitFromIterable(self):
-        self.assertTrue(isinstance(range(10), collections.Iterable))
+        self.assertTrue(isinstance(range(10), Iterable))
         s = ConstBitStream(range(12))
         self.assertEqual(s, '0x7ff')
 

From b2a27f33c1efda32175409ac5a0bc78cad10aa59 Mon Sep 17 00:00:00 2001
From: Karthikeyan Singaravelan <tir.karthi@gmail.com>
Date: Wed, 22 Jan 2020 23:15:57 +0530
Subject: [PATCH 2/2] Fix warnings regarding invalid escape sequences.

---
 bitstring.py | 2 +-
 doc/conf.py  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/bitstring.py b/bitstring.py
index 14c93881..b7696b9f 100644
--- a/bitstring.py
+++ b/bitstring.py
@@ -1,5 +1,5 @@
 #!/usr/bin/env python
-"""
+r"""
 This package defines classes that simplify bit-wise creation, manipulation and
 interpretation of data.
 
diff --git a/doc/conf.py b/doc/conf.py
index 94a58d8c..3802f3f9 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -215,7 +215,7 @@
 \\cleardoublepage
 """ % release
 
-latex_elements = {'preamble': '\setcounter{tocdepth}{2}\definecolor{VerbatimBorderColor}{rgb}{1,1,1}',
+latex_elements = {'preamble': r'\setcounter{tocdepth}{2}\definecolor{VerbatimBorderColor}{rgb}{1,1,1}',
                   'fncychap': '\\usepackage[Sonny]{fncychap}',
                   'maketitle': titlepage,
                   'papersize': 'a4paper',