Remove support for Python 2

  * Remove all usage of the `six` library
  * Remove declared support for Python 2
  * Update tox.ini to remove `py27` environment
  * Update Github workflows to no longer test against Python 2.7

Closes: #401

.github/workflows/main.yml

@@ -15,14 +15,12 @@ jobs:
       fail-fast: false
       matrix:
         python-version:
-          - "2.7"
           - "3.4"
           - "3.5"
           - "3.6"
           - "3.7"
           - "3.8"
           - "3.9"
-          - "pypy2"
           - "pypy3"
     steps:
     - uses: actions/checkout@v2

README.rst

@@ -5,7 +5,7 @@ library.
 
 =========================  ========================================
 Current version            2.2.0
-Supported Python versions  2.7, 3.4 - 3.9
+Supported Python versions  3.4 - 3.9
 License                    New BSD
 Project home               https://github.com/mjs/imapclient/
 PyPI                       https://pypi.python.org/pypi/IMAPClient

doc/src/concepts.rst

@@ -102,13 +102,6 @@ When constructing a custom context it is usually best to start with
 the default context, created by the ``ssl`` module, and modify it to
 suit your needs.
 
-.. warning::
-
-  Users of Python 2.7.0 - 2.7.8 can use TLS but cannot configure
-  the settings via an ``ssl.SSLContext``. These Python versions are
-  also not capable of proper certification verification. It is highly
-  encouraged to upgrade to a more recent version of Python.
-
 The following example shows how to to disable certification
 verification and certificate host name checks if required.
 

doc/src/index.rst

@@ -30,7 +30,7 @@ explains IMAP in detail. Other RFCs also apply to various extensions
 to the base protocol. These are referred to in the documentation below
 where relevant.
 
-Python versions 2.7 and 3.4 through 3.9 are officially supported.
+Python versions 3.4 through 3.9 are officially supported.
 
 Getting Started
 ---------------

imapclient/config.py

@@ -8,10 +8,9 @@
 from os import environ, path
 import ssl
 
-from six import iteritems
-from six.moves.configparser import SafeConfigParser, NoOptionError
-from six.moves.urllib.request import urlopen
-from six.moves.urllib.parse import urlencode
+import configparser
+import urllib.parse
+import urllib.request
 
 import imapclient
 
@@ -45,7 +44,7 @@ def parse_config_file(filename):
     Used by livetest.py and interact.py
     """
 
-    parser = SafeConfigParser(get_string_config_defaults())
+    parser = configparser.SafeConfigParser(get_string_config_defaults())
     with open(filename, "r") as fh:
         parser.readfp(fh)
 
@@ -62,7 +61,7 @@ def parse_config_file(filename):
 
 def get_string_config_defaults():
     out = {}
-    for k, v in iteritems(get_config_defaults()):
+    for k, v in get_config_defaults().items():
         if v is True:
             v = "true"
         elif v is False:
@@ -80,7 +79,7 @@ def _read_config_section(parser, section):
     def get_allowing_none(name, typefunc):
         try:
             v = parser.get(section, name)
-        except NoOptionError:
+        except configparser.NoOptionError:
             return None
         if not v:
             return None
@@ -133,7 +132,8 @@ def refresh_oauth2_token(hostname, client_id, client_secret, refresh_token):
         refresh_token=refresh_token.encode("ascii"),
         grant_type=b"refresh_token",
     )
-    response = urlopen(url, urlencode(post).encode("ascii")).read()
+    response = urllib.request.urlopen(
+        url, urllib.parse.urlencode(post).encode("ascii")).read()
     return json.loads(response.decode("ascii"))["access_token"]
 
 

imapclient/imap_utf7.py

@@ -9,7 +9,6 @@
 from __future__ import unicode_literals
 
 import binascii
-from six import binary_type, text_type, byte2int, iterbytes, unichr
 
 
 def encode(s):
@@ -18,7 +17,7 @@ def encode(s):
     Input is unicode; output is bytes (Python 3) or str (Python 2). If
     non-unicode input is provided, the input is returned unchanged.
     """
-    if not isinstance(s, text_type):
+    if not isinstance(s, str):
         return s
 
     res = bytearray()
@@ -56,8 +55,8 @@ def consume_b64_buffer(buf):
     return bytes(res)
 
 
-AMPERSAND_ORD = byte2int(b"&")
-DASH_ORD = byte2int(b"-")
+AMPERSAND_ORD = ord("&")
+DASH_ORD = ord("-")
 
 
 def decode(s):
@@ -67,13 +66,13 @@ def decode(s):
     unicode. If non-bytes/str input is provided, the input is returned
     unchanged.
     """
-    if not isinstance(s, binary_type):
+    if not isinstance(s, bytes):
         return s
 
     res = []
     # Store base64 substring that will be decoded once stepping on end shift character
     b64_buffer = bytearray()
-    for c in iterbytes(s):
+    for c in s:
         # Shift character without anything in buffer -> starts storing base64 substring
         if c == AMPERSAND_ORD and not b64_buffer:
             b64_buffer.append(c)
@@ -90,7 +89,7 @@ def decode(s):
             b64_buffer.append(c)
         # No buffer initialized yet, should be an ASCII printable char
         else:
-            res.append(unichr(c))
+            res.append(chr(c))
 
     # Decode the remaining buffer if any
     if b64_buffer:

imapclient/imapclient.py

@@ -17,8 +17,6 @@
 from operator import itemgetter
 from logging import LoggerAdapter, getLogger
 
-from six import moves, iteritems, text_type, integer_types, PY3, binary_type, iterbytes
-
 from . import exceptions
 from . import imap4
 from . import response_lexer
@@ -28,8 +26,6 @@
 from .response_parser import parse_response, parse_message_list, parse_fetch_response
 from .util import to_bytes, to_unicode, assert_imap_protocol, chunk
 
-xrange = moves.xrange
-
 try:
     from select import poll
 
@@ -38,9 +34,6 @@
     # Fallback to select() on systems that don't support poll()
     POLL_SUPPORT = False
 
-if PY3:
-    long = int  # long is just int in python3
-
 
 logger = getLogger(__name__)
 
@@ -744,11 +737,11 @@ def _proc_folder_list(self, folder_data):
         ret = []
         parsed = parse_response(folder_data)
         for flags, delim, name in chunk(parsed, size=3):
-            if isinstance(name, (int, long)):
+            if isinstance(name, int):
                 # Some IMAP implementations return integer folder names
                 # with quotes. These get parsed to ints so convert them
                 # back to strings.
-                name = text_type(name)
+                name = str(name)
             elif self.folder_encode:
                 name = decode_utf7(name)
 
@@ -838,7 +831,7 @@ def _process_select_response(self, resp):
                 if key == b"PERMANENTFLAGS":
                     out[key] = tuple(match.group("data").split())
 
-        for key, value in iteritems(untagged):
+        for key, value in untagged.items():
             key = key.upper()
             if key in (b"OK", b"PERMANENTFLAGS"):
                 continue  # already handled above
@@ -1190,7 +1183,7 @@ def sort(self, sort_criteria, criteria="ALL", charset="UTF-8"):
         ]
         args.extend(_normalise_search_criteria(criteria, charset))
         ids = self._raw_command_untagged(b"SORT", args, unpack=True)
-        return [long(i) for i in ids.split()]
+        return [int(i) for i in ids.split()]
 
     def thread(self, algorithm="REFERENCES", criteria="ALL", charset="UTF-8"):
         """Return a list of messages threads from the currently
@@ -1276,7 +1269,7 @@ def get_gmail_labels(self, messages):
         response = self.fetch(messages, [b"X-GM-LABELS"])
         response = self._filter_fetch_dict(response, b"X-GM-LABELS")
         return {
-            msg: utf7_decode_sequence(labels) for msg, labels in iteritems(response)
+            msg: utf7_decode_sequence(labels) for msg, labels in response.items()
         }
 
     def add_gmail_labels(self, messages, labels, silent=False):
@@ -1405,10 +1398,7 @@ def append(self, folder, msg, flags=(), msg_time=None):
         """
         if msg_time:
             time_val = '"%s"' % datetime_to_INTERNALDATE(msg_time)
-            if PY3:
-                time_val = to_unicode(time_val)
-            else:
-                time_val = to_bytes(time_val)
+            time_val = to_unicode(time_val)
         else:
             time_val = None
         return self._command_and_check(
@@ -1528,7 +1518,7 @@ def getacl(self, folder):
         data = self._command_and_check("getacl", self._normalise_folder(folder))
         parts = list(response_lexer.TokenSource(data))
         parts = parts[1:]  # First item is folder name
-        return [(parts[i], parts[i + 1]) for i in xrange(0, len(parts), 2)]
+        return [(parts[i], parts[i + 1]) for i in range(0, len(parts), 2)]
 
     @require_capability("ACL")
     def setacl(self, folder, who, what):
@@ -1730,8 +1720,7 @@ def _command_and_check(self, command, *args, **kwargs):
         assert not kwargs, "unexpected keyword args: " + ", ".join(kwargs)
 
         if uid and self.use_uid:
-            if PY3:
-                command = to_unicode(command)  # imaplib must die
+            command = to_unicode(command)  # imaplib must die
             typ, data = self._imap.uid(command, *args)
         else:
             meth = getattr(self._imap, to_unicode(command))
@@ -1749,7 +1738,7 @@ def _gm_label_store(self, cmd, messages, labels, silent):
             cmd, messages, self._normalise_labels(labels), b"X-GM-LABELS", silent=silent
         )
         return (
-            {msg: utf7_decode_sequence(labels) for msg, labels in iteritems(response)}
+            {msg: utf7_decode_sequence(labels) for msg, labels in response.items()}
             if response
             else None
         )
@@ -1772,17 +1761,17 @@ def _store(self, cmd, messages, flags, fetch_key, silent):
         return self._filter_fetch_dict(parse_fetch_response(data), fetch_key)
 
     def _filter_fetch_dict(self, fetch_dict, key):
-        return dict((msgid, data[key]) for msgid, data in iteritems(fetch_dict))
+        return dict((msgid, data[key]) for msgid, data in fetch_dict.items())
 
     def _normalise_folder(self, folder_name):
-        if isinstance(folder_name, binary_type):
+        if isinstance(folder_name, bytes):
             folder_name = folder_name.decode("ascii")
         if self.folder_encode:
             folder_name = encode_utf7(folder_name)
         return _quote(folder_name)
 
     def _normalise_labels(self, labels):
-        if isinstance(labels, (text_type, binary_type)):
+        if isinstance(labels, (str, bytes)):
             labels = (labels,)
         return [_quote(encode_utf7(l)) for l in labels]
 
@@ -1796,7 +1785,7 @@ def welcome(self):
 
 
 def _quote(arg):
-    if isinstance(arg, text_type):
+    if isinstance(arg, str):
         arg = arg.replace("\\", "\\\\")
         arg = arg.replace('"', '\\"')
         q = '"'
@@ -1813,7 +1802,7 @@ def _normalise_search_criteria(criteria, charset=None):
     if not charset:
         charset = "us-ascii"
 
-    if isinstance(criteria, (text_type, binary_type)):
+    if isinstance(criteria, (str, bytes)):
         return [to_bytes(criteria, charset)]
 
     out = []
@@ -1834,7 +1823,7 @@ def _normalise_search_criteria(criteria, charset=None):
 
 
 def _normalise_sort_criteria(criteria, charset=None):
-    if isinstance(criteria, (text_type, binary_type)):
+    if isinstance(criteria, (str, bytes)):
         criteria = [criteria]
     return b"(" + b" ".join(to_bytes(item).upper() for item in criteria) + b")"
 
@@ -1845,7 +1834,7 @@ class _literal(bytes):
     pass
 
 
-class _quoted(binary_type):
+class _quoted(bytes):
     """
     This class holds a quoted bytes value which provides access to the
     unquoted value via the *original* attribute.
@@ -1892,7 +1881,7 @@ def _join_and_paren(items):
 
 
 def _normalise_text_list(items):
-    if isinstance(items, (text_type, binary_type)):
+    if isinstance(items, (str, bytes)):
         items = (items,)
     return (to_unicode(c) for c in items)
 
@@ -1901,14 +1890,14 @@ def join_message_ids(messages):
     """Convert a sequence of messages ids or a single integer message id
     into an id byte string for use with IMAP commands
     """
-    if isinstance(messages, (text_type, binary_type, integer_types)):
+    if isinstance(messages, (str, bytes, int)):
         messages = (to_bytes(messages),)
     return b",".join(_maybe_int_to_bytes(m) for m in messages)
 
 
 def _maybe_int_to_bytes(val):
-    if isinstance(val, integer_types):
-        return str(val).encode("us-ascii") if PY3 else str(val)
+    if isinstance(val, int):
+        return str(val).encode("us-ascii")
     return to_bytes(val)
 
 
@@ -1943,7 +1932,7 @@ def as_triplets(items):
 
 
 def _is8bit(data):
-    return isinstance(data, _literal) or any(b > 127 for b in iterbytes(data))
+    return isinstance(data, _literal) or any(b > 127 for b in data)
 
 
 def _iter_with_last(items):
@@ -1964,7 +1953,7 @@ def __init__(self, d):
         self._d = d
 
     def iteritems(self):
-        for key, value in iteritems(self._d):
+        for key, value in self._d.items():
             yield to_bytes(key), value
 
     # For Python 3 compatibility.
@@ -1998,7 +1987,7 @@ def pop(self, ink, default=_not_present):
 
     def _gen_keys(self, k):
         yield k
-        if isinstance(k, binary_type):
+        if isinstance(k, bytes):
             yield to_unicode(k)
         else:
             yield to_bytes(k)
@@ -2037,7 +2026,7 @@ class IMAPlibLoggerAdapter(LoggerAdapter):
     def process(self, msg, kwargs):
         # msg is usually unicode but see #367. Convert bytes to
         # unicode if required.
-        if isinstance(msg, binary_type):
+        if isinstance(msg, bytes):
             msg = msg.decode("ascii", "ignore")
 
         for command in ("LOGIN", "AUTHENTICATE"):

imapclient/interact.py

@@ -10,8 +10,6 @@
 from getpass import getpass
 from optparse import OptionParser
 
-from six import iteritems
-
 from .config import parse_config_file, create_client_from_config, get_config_defaults
 
 
@@ -93,7 +91,7 @@ def command_line():
         # Scan through options, filling in defaults and prompting when
         # a compulsory option wasn't provided.
         compulsory_opts = ("host", "username", "password")
-        for name, default_value in iteritems(get_config_defaults()):
+        for name, default_value in get_config_defaults().items():
             value = getattr(opts, name, default_value)
             if name in compulsory_opts and value is None:
                 value = getpass(name + ": ")