Remove PY2 compatibility code

Python 2 is no longer supported in PyOTA.
Remove glue code that made it possible to run the same
code on both versions, as it is no longer needed.

Changes:
 - Remove imports from `six` package
 - Remove imports from `__future__` package
 - Add some Py3 syntax
 - Remove encoding spec from files as PY3's default is utf-8
 - Update setup.py, simplify dependencies, include metadata
   in the built sdist and wheel about supported python version
 - Remove `noinspection` comments

Author: lzpap

examples/address_generator.py

@@ -1,18 +1,12 @@
-# coding=utf-8
 """
 Generates a shiny new IOTA address that you can use for transfers!
 """
 
-from __future__ import absolute_import, division, print_function, \
-    unicode_literals
-
 from argparse import ArgumentParser
 from getpass import getpass as secure_input
 from sys import argv
 from typing import Optional, Text
 
-from six import binary_type, moves as compat, text_type
-
 from iota import Iota, __version__
 from iota.crypto.addresses import AddressGenerator
 from iota.crypto.types import Seed
@@ -38,13 +32,13 @@ def main(uri, index, count, security, checksum):
     # Here's where all the magic happens!
     api_response = api.get_new_addresses(index, count, security, checksum)
     for addy in api_response['addresses']:
-        print(binary_type(addy).decode('ascii'))
+        print(bytes(addy).decode('ascii'))
 
     print('')
 
 
 def get_seed():
-    # type: () -> binary_type
+    # type: () -> bytes
     """
     Prompts the user securely for their seed.
     """
@@ -66,18 +60,18 @@ def output_seed(seed):
         'WARNING: Anyone who has your seed can spend your IOTAs! '
         'Clear the screen after recording your seed!'
     )
-    compat.input('')
+    input('')
     print('Your seed is:')
     print('')
-    print(binary_type(seed).decode('ascii'))
+    print(bytes(seed).decode('ascii'))
     print('')
 
     print(
         'Clear the screen to prevent shoulder surfing, '
         'and press return to continue.'
     )
     print('https://en.wikipedia.org/wiki/Shoulder_surfing_(computer_security)')
-    compat.input('')
+    input('')
 
 
 if __name__ == '__main__':
@@ -88,7 +82,7 @@ def output_seed(seed):
 
     parser.add_argument(
         '--uri',
-        type=text_type,
+        type=str,
         default='http://localhost:14265/',
 
         help=(

examples/hello_world.py

@@ -1,18 +1,13 @@
-# coding=utf-8
 """
 Simple "Hello, world!" example that sends a `getNodeInfo` command to
 your friendly neighborhood node.
 """
 
-from __future__ import absolute_import, division, print_function, \
-    unicode_literals
-
 from argparse import ArgumentParser
 from pprint import pprint
 from sys import argv
 from typing import Text
 from httpx.exceptions import NetworkError
-from six import text_type
 
 from iota import BadApiResponse, StrictIota, __version__
 
@@ -44,7 +39,7 @@ def main(uri):
 
     parser.add_argument(
         '--uri',
-        type=text_type,
+        type=str,
         default='http://localhost:14265/',
 
         help=(

examples/local_pow.py

@@ -1,6 +1,3 @@
-from __future__ import absolute_import, division, print_function, \
-    unicode_literals
-
 import iota
 from pprint import pprint
 

examples/mam_js_send.py

@@ -1,6 +1,3 @@
-# coding=utf-8
-from __future__ import absolute_import, division, print_function, \
-    unicode_literals
 
 import codecs
 import json
@@ -10,7 +7,6 @@
 from typing import List, Optional, Text
 
 import filters as f
-from six import binary_type, text_type
 
 from iota import Bundle, Iota, TransactionTrytes
 from iota.bin import IotaCommandLineApp
@@ -71,14 +67,14 @@ def execute(self, api, **arguments):
                 mam_encrypt_path,
 
                 # Required arguments
-                binary_type(api.seed),
+                bytes(api.seed),
                 message,
 
                 # Options
-                '--channel-key-index', text_type(channel_key_index),
-                '--start', text_type(start),
-                '--count', text_type(count),
-                '--security-level', text_type(security_level),
+                '--channel-key-index', str(channel_key_index),
+                '--start', str(start),
+                '--count', str(count),
+                '--security-level', str(security_level),
             ],
 
             check=True,

examples/multisig.py

@@ -1,4 +1,3 @@
-# coding=utf-8
 """
 Example of how to use PyOTA's multisig feature.
 
@@ -10,9 +9,6 @@
   - https://github.com/iotaledger/wiki/blob/master/multisigs.md
 """
 
-from __future__ import absolute_import, division, print_function, \
-    unicode_literals
-
 from typing import List
 
 from iota import Address, Bundle, BundleValidator, ProposedTransaction, Tag, \
@@ -35,7 +31,6 @@
 ##
 # Create digest 1 of 3.
 #
-# noinspection SpellCheckingInspection
 api_1 = MultisigIota(
     adapter='http://localhost:14265',
 
@@ -64,7 +59,6 @@
 ##
 # Create digest 2 of 3.
 #
-# noinspection SpellCheckingInspection
 api_2 = MultisigIota(
     adapter='http://localhost:14265',
 
@@ -83,7 +77,6 @@
 ##
 # Create digest 3 of 3.
 #
-# noinspection SpellCheckingInspection
 api_3 = MultisigIota(
     adapter='http://localhost:14265',
 
@@ -128,7 +121,6 @@
 the change from the transaction!
 """
 
-# noinspection SpellCheckingInspection
 pmt_result = api_1.prepare_multisig_transfer(
     # These are the transactions that will spend the IOTAs.
     # You can divide up the IOTAs to send to multiple addresses if you

examples/routingwrapper_pow.py

@@ -1,4 +1,3 @@
-# coding=utf-8
 """
 Simple example using the RoutingWrapper to route API requests to
 different nodes.
@@ -18,7 +17,6 @@
 api = Iota(router, seed=b'SEED9GOES9HERE')
 
 # Example of sending a transfer using the adapter.
-# noinspection SpellCheckingInspection
 bundle = api.send_transfer(
     depth=3,
 

examples/send_transfer.py

@@ -1,4 +1,3 @@
-# coding=utf-8
 """
 Example script that shows how to use PyOTA to send a transfer to an address.
 """
@@ -13,7 +12,6 @@
   Tag,
   TryteString,
 )
-from six import text_type
 from address_generator import get_seed, output_seed
 
 
@@ -60,7 +58,7 @@ def main(address, depth, message, tag, uri, value):
 
     parser.add_argument(
         '--address',
-        type=text_type,
+        type=str,
         default=b'RECEIVINGWALLETADDRESSGOESHERE9WITHCHECKSUMANDSECURITYLEVELB999999999999999999999999999999',
         help=
         'Receiving address'
@@ -78,7 +76,7 @@ def main(address, depth, message, tag, uri, value):
 
     parser.add_argument(
         '--message',
-        type=text_type,
+        type=str,
         default='Hello World!',
         help=
         'Transfer message.'
@@ -87,7 +85,7 @@ def main(address, depth, message, tag, uri, value):
 
     parser.add_argument(
         '--tag',
-        type=text_type,
+        type=str,
         default=b'EXAMPLE',
         help=
         'Transfer tag'
@@ -96,7 +94,7 @@ def main(address, depth, message, tag, uri, value):
 
     parser.add_argument(
         '--uri',
-        type=text_type,
+        type=str,
         default='http://localhost:14265/',
         help=
         'URI of the node to connect to.'

iota/__init__.py

@@ -1,6 +1,3 @@
-# coding=utf-8
-from __future__ import absolute_import, division, print_function, \
-    unicode_literals
 
 # Define a few magic constants.
 DEFAULT_PORT = 14265

iota/adapter/__init__.py

@@ -1,6 +1,3 @@
-# coding=utf-8
-from __future__ import absolute_import, division, print_function, \
-    unicode_literals
 
 import json
 from abc import ABCMeta, abstractmethod as abstract_method
@@ -11,8 +8,6 @@
 from typing import Container, Dict, List, Optional, Text, Tuple, Union
 from httpx import AsyncClient, Response, codes, auth
 import asyncio
-from six import PY2, binary_type, iteritems, moves as compat, text_type, \
-    add_metaclass
 
 from iota.exceptions import with_context
 from iota.json import JsonEncoder
@@ -28,13 +23,6 @@
     'resolve_adapter',
 ]
 
-if PY2:
-    # Fix an error when importing this package using the ``imp`` library
-    # (note: ``imp`` is deprecated since Python 3.4 in favor of
-    # ``importlib``).
-    # https://docs.python.org/3/library/imp.html
-    # https://travis-ci.org/iotaledger/iota.py/jobs/191974244
-    __all__ = map(binary_type, __all__)
 
 API_VERSION = '1'
 """
@@ -52,12 +40,7 @@
 """
 
 # Load SplitResult for IDE type hinting and autocompletion.
-if PY2:
-    # noinspection PyCompatibility,PyUnresolvedReferences
-    from urlparse import SplitResult
-else:
-    # noinspection PyCompatibility,PyUnresolvedReferences
-    from urllib.parse import SplitResult
+from urllib.parse import SplitResult, urlsplit
 
 def async_return(result):
   """
@@ -97,7 +80,7 @@ def resolve_adapter(uri):
     if isinstance(uri, BaseAdapter):
         return uri
 
-    parsed = compat.urllib_parse.urlsplit(uri)  # type: SplitResult
+    parsed = urlsplit(uri)  # type: SplitResult
 
     if not parsed.scheme:
         raise with_context(
@@ -133,7 +116,6 @@ class AdapterMeta(ABCMeta):
     Automatically registers new adapter classes in ``adapter_registry``.
     """
 
-    # noinspection PyShadowingBuiltins
     def __init__(cls, what, bases=None, dict=None):
         super(AdapterMeta, cls).__init__(what, bases, dict)
 
@@ -154,8 +136,7 @@ def configure(cls, parsed):
         return cls(parsed)
 
 
-@add_metaclass(AdapterMeta)
-class BaseAdapter(object):
+class BaseAdapter(object, metaclass=AdapterMeta):
     """
     Interface for IOTA API adapters.
 
@@ -242,7 +223,7 @@ class HttpAdapter(BaseAdapter):
     :param AdapterSpec uri:
         URI or adapter instance.
 
-        If ``uri`` is a ``text_type``, it is parsed to extract ``scheme``,
+        If ``uri`` is a ``str``, it is parsed to extract ``scheme``,
         ``hostname`` and ``port``.
 
     :param Optional[int] timeout:
@@ -284,8 +265,8 @@ def __init__(self, uri, timeout=None, authentication=None):
         self.timeout = timeout
         self.authentication = authentication
 
-        if isinstance(uri, text_type):
-            uri = compat.urllib_parse.urlsplit(uri)  # type: SplitResult
+        if isinstance(uri, str):
+            uri = urlsplit(uri)  # type: SplitResult
 
         if uri.scheme not in self.supported_protocols:
             raise with_context(
@@ -312,7 +293,6 @@ def __init__(self, uri, timeout=None, authentication=None):
             )
 
         try:
-            # noinspection PyStatementEffect
             uri.port
         except ValueError:
             raise with_context(
@@ -344,7 +324,7 @@ def get_uri(self):
     async def send_request(self, payload, **kwargs):
         # type: (dict, dict) -> dict
         kwargs.setdefault('headers', {})
-        for key, value in iteritems(self.DEFAULT_HEADERS):
+        for key, value in self.DEFAULT_HEADERS.items():
             kwargs['headers'].setdefault(key, value)
 
         response = await self._send_http_request(
@@ -539,7 +519,6 @@ class MockAdapter(BaseAdapter):
     """
     supported_protocols = ('mock',)
 
-    # noinspection PyUnusedLocal
     @classmethod
     def configure(cls, uri):
         return cls()

iota/adapter/wrappers.py

@@ -1,21 +1,14 @@
-# coding=utf-8
-from __future__ import absolute_import, division, print_function, \
-    unicode_literals
-
 from abc import ABCMeta, abstractmethod as abstract_method
 from typing import Dict, Text
 
-from six import add_metaclass
-
 from iota.adapter import AdapterSpec, BaseAdapter, resolve_adapter
 
 __all__ = [
     'RoutingWrapper',
 ]
 
 
-@add_metaclass(ABCMeta)
-class BaseWrapper(BaseAdapter):
+class BaseWrapper(BaseAdapter, metaclass=ABCMeta):
     """
     Base functionality for "adapter wrappers", used to extend the
     functionality of IOTA adapters.