diff --git a/httpie/cli/constants.py b/httpie/cli/constants.py
index 5b1d5986..e0690e02 100644
--- a/httpie/cli/constants.py
+++ b/httpie/cli/constants.py
@@ -5,15 +5,6 @@ import enum
 import re
 
 
-# TODO: Use MultiDict for headers once added to `requests`.
-# <https://github.com/jakubroztocil/httpie/issues/130>
-
-
-# ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
-# <https://tools.ietf.org/html/rfc3986#section-3.1>
-from enum import Enum
-
-
 URL_SCHEME_RE = re.compile(r'^[a-z][a-z0-9.+-]*://', re.IGNORECASE)
 
 HTTP_POST = 'POST'
diff --git a/httpie/cli/requestitems.py b/httpie/cli/requestitems.py
index 3168c39c..e75e0395 100644
--- a/httpie/cli/requestitems.py
+++ b/httpie/cli/requestitems.py
@@ -1,5 +1,4 @@
 import os
-from io import BytesIO
 from typing import Callable, Dict, IO, List, Optional, Tuple, Union
 
 from httpie.cli.argtypes import KeyValueArg
diff --git a/httpie/core.py b/httpie/core.py
index 5092c5ea..43b4255c 100644
--- a/httpie/core.py
+++ b/httpie/core.py
@@ -283,6 +283,6 @@ def decode_raw_args(
     """
     return [
         arg.decode(stdin_encoding)
-        if type(arg) == bytes else arg
+        if type(arg) is bytes else arg
         for arg in args
     ]
diff --git a/setup.py b/setup.py
index a10fd8d7..5204cadf 100644
--- a/setup.py
+++ b/setup.py
@@ -15,6 +15,7 @@ class PyTest(TestCommand):
     and runs the tests with no fancy stuff like parallel execution.
 
     """
+
     def finalize_options(self):
         TestCommand.finalize_options(self)
         self.test_args = [
diff --git a/tests/test_downloads.py b/tests/test_downloads.py
index 381bd030..f32043b8 100644
--- a/tests/test_downloads.py
+++ b/tests/test_downloads.py
@@ -5,7 +5,6 @@ from urllib.request import urlopen
 
 import pytest
 import mock
-import requests
 from requests.structures import CaseInsensitiveDict
 
 from httpie.downloads import (
diff --git a/tests/test_httpie.py b/tests/test_httpie.py
index 877d5c84..5a297071 100644
--- a/tests/test_httpie.py
+++ b/tests/test_httpie.py
@@ -182,4 +182,4 @@ def test_json_input_preserve_order(httpbin_both):
              'order:={"map":{"1":"first","2":"second"}}')
     assert HTTP_OK in r
     assert r.json['data'] == \
-           '{"order": {"map": {"1": "first", "2": "second"}}}'
+        '{"order": {"map": {"1": "first", "2": "second"}}}'