diff --git a/setup.py b/setup.py
index 9707d74..539de26 100644
--- a/setup.py
+++ b/setup.py
@@ -2,9 +2,10 @@
 # -*- coding: utf-8 -*-
 
 from pathlib import Path
-from setuptools import setup, find_packages
 
-from src.wireviz import __version__, CMD_NAME, APP_URL
+from setuptools import find_packages, setup
+
+from src.wireviz import APP_URL, CMD_NAME, __version__
 
 README_PATH = Path(__file__).parent / 'docs' / 'README.md'
 
diff --git a/src/wireviz/DataClasses.py b/src/wireviz/DataClasses.py
index d6ccf75..c8a39ce 100644
--- a/src/wireviz/DataClasses.py
+++ b/src/wireviz/DataClasses.py
@@ -1,13 +1,12 @@
 # -*- coding: utf-8 -*-
 
+from dataclasses import InitVar, dataclass, field
 from enum import Enum, auto
-from typing import Dict, List, Optional, Tuple, Union
-from dataclasses import dataclass, field, InitVar
 from pathlib import Path
+from typing import Dict, List, Optional, Tuple, Union
 
-from wireviz.wv_helper import int2tuple, aspect_ratio
-from wireviz.wv_colors import Color, Colors, ColorMode, ColorScheme, COLOR_CODES
-
+from wireviz.wv_colors import COLOR_CODES, Color, ColorMode, Colors, ColorScheme
+from wireviz.wv_helper import aspect_ratio, int2tuple
 
 # Each type alias have their legal values described in comments - validation might be implemented in the future
 PlainText = str # Text not containing HTML tags nor newlines
diff --git a/src/wireviz/Harness.py b/src/wireviz/Harness.py
index 31f0675..940aaf4 100644
--- a/src/wireviz/Harness.py
+++ b/src/wireviz/Harness.py
@@ -1,25 +1,57 @@
 # -*- coding: utf-8 -*-
 
-from graphviz import Graph
-from collections import Counter
-from typing import Any, List, Union
-from dataclasses import dataclass
-from pathlib import Path
-from itertools import zip_longest
 import re
+from collections import Counter
+from dataclasses import dataclass
+from itertools import zip_longest
+from pathlib import Path
+from typing import Any, List, Union
 
-from wireviz import wv_colors, __version__, APP_NAME, APP_URL
-from wireviz.DataClasses import Cable, Connector, MatePin, MateComponent, Metadata, Options, Tweak, Side
+from graphviz import Graph
+
+from wireviz import APP_NAME, APP_URL, __version__, wv_colors
+from wireviz.DataClasses import (
+    Cable,
+    Connector,
+    MateComponent,
+    MatePin,
+    Metadata,
+    Options,
+    Tweak,
+	Side,
+)
+from wireviz.wv_bom import (
+    HEADER_MPN,
+    HEADER_PN,
+    HEADER_SPN,
+    bom_list,
+    component_table_entry,
+    generate_bom,
+    get_additional_component_table,
+    pn_info_string,
+)
 from wireviz.wv_colors import get_color_hex, translate_color
-from wireviz.wv_gv_html import nested_html_table, \
-    html_bgcolor_attr, html_bgcolor, html_colorbar, \
-    html_image, html_caption, remove_links, html_line_breaks
-from wireviz.wv_bom import pn_info_string, component_table_entry, \
-    get_additional_component_table, bom_list, generate_bom, \
-    HEADER_PN, HEADER_MPN, HEADER_SPN
+from wireviz.wv_gv_html import (
+    html_bgcolor,
+    html_bgcolor_attr,
+    html_caption,
+    html_colorbar,
+    html_image,
+    html_line_breaks,
+    nested_html_table,
+    remove_links,
+)
+from wireviz.wv_helper import (
+    awg_equiv,
+    flatten2d,
+    is_arrow,
+    mm2_equiv,
+    open_file_read,
+    open_file_write,
+    tuplelist2tsv,
+)
 from wireviz.wv_html import generate_html_output
-from wireviz.wv_helper import awg_equiv, mm2_equiv, tuplelist2tsv, flatten2d, \
-    open_file_read, open_file_write, is_arrow
+
 
 @dataclass
 class Harness:
diff --git a/src/wireviz/build_examples.py b/src/wireviz/build_examples.py
index f098a59..ee486b3 100755
--- a/src/wireviz/build_examples.py
+++ b/src/wireviz/build_examples.py
@@ -3,15 +3,15 @@
 
 import argparse
 import os
-from pathlib import Path
 import sys
+from pathlib import Path
 
 script_path = Path(__file__).absolute()
 
 sys.path.insert(0, str(script_path.parent.parent))  # to find wireviz module
-from wireviz import wireviz, __version__, APP_NAME
-from wv_helper import open_file_write, open_file_read, open_file_append
+from wv_helper import open_file_append, open_file_read, open_file_write
 
+from wireviz import APP_NAME, __version__, wireviz
 
 dir = script_path.parent.parent.parent
 readme = 'readme.md'
diff --git a/src/wireviz/wireviz.py b/src/wireviz/wireviz.py
index e76d216..83f8ed2 100755
--- a/src/wireviz/wireviz.py
+++ b/src/wireviz/wireviz.py
@@ -1,8 +1,8 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
-from pathlib import Path
 import sys
+from pathlib import Path
 from typing import Any, Dict, List, Tuple
 
 import yaml
@@ -12,7 +12,13 @@ if __name__ == '__main__':
 
 from wireviz.DataClasses import Metadata, Options, Tweak
 from wireviz.Harness import Harness
-from wireviz.wv_helper import expand, get_single_key_and_value, is_arrow, open_file_read, smart_file_resolve
+from wireviz.wv_helper import (
+    expand,
+    get_single_key_and_value,
+    is_arrow,
+    open_file_read,
+    smart_file_resolve,
+)
 
 
 def parse_text(yaml_str: str, file_out: (str, Path) = None, output_formats: (None, str, Tuple[str]) = ('html','png','svg','tsv'), return_types: (None, str, Tuple[str]) = None, image_paths: List = []) -> Any:
diff --git a/src/wireviz/wv_cli.py b/src/wireviz/wv_cli.py
index eb94633..d3f80ce 100644
--- a/src/wireviz/wv_cli.py
+++ b/src/wireviz/wv_cli.py
@@ -1,16 +1,16 @@
 # -*- coding: utf-8 -*-
 
 import os
-from pathlib import Path
 import sys
+from pathlib import Path
 
 import click
 
 if __name__ == '__main__':
     sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..'))
 
-from wireviz import APP_NAME, __version__
 import wireviz.wireviz as wv
+from wireviz import APP_NAME, __version__
 from wireviz.wv_helper import open_file_read
 
 format_codes = {'c': 'csv', 'g': 'gv', 'h': 'html', 'p': 'png', 'P': 'pdf', 's': 'svg', 't': 'tsv'}
diff --git a/src/wireviz/wv_gv_html.py b/src/wireviz/wv_gv_html.py
index ff8b4ea..e35084f 100644
--- a/src/wireviz/wv_gv_html.py
+++ b/src/wireviz/wv_gv_html.py
@@ -1,12 +1,13 @@
 # -*- coding: utf-8 -*-
 
-from typing import List, Optional, Union
 import re
+from typing import List, Optional, Union
 
 from wireviz.DataClasses import Color
 from wireviz.wv_colors import translate_color
 from wireviz.wv_helper import remove_links
 
+
 def nested_html_table(rows: List[Union[str, List[Optional[str]], None]], table_attrs: str = '') -> str:
     # input: list, each item may be scalar or list
     # output: a parent table with one child table per parent item that is list, and one cell per parent item that is scalar
@@ -73,6 +74,7 @@ def html_caption(image):
 
 def html_size_attr(image):
     from wireviz.DataClasses import Image
+
     # Return Graphviz HTML attributes to specify minimum or fixed size of a TABLE or TD object
     return ((f' width="{image.width}"'   if image.width else '')
         +   (f' height="{image.height}"' if image.height else '')
diff --git a/src/wireviz/wv_helper.py b/src/wireviz/wv_helper.py
index 01bccaa..844556d 100644
--- a/src/wireviz/wv_helper.py
+++ b/src/wireviz/wv_helper.py
@@ -1,8 +1,8 @@
 # -*- coding: utf-8 -*-
 
-from typing import Dict, List
-from pathlib import Path
 import re
+from pathlib import Path
+from typing import Dict, List
 
 awg_equiv_table = {
     '0.09': '28',
diff --git a/src/wireviz/wv_html.py b/src/wireviz/wv_html.py
index 37773f7..9a9a968 100644
--- a/src/wireviz/wv_html.py
+++ b/src/wireviz/wv_html.py
@@ -1,13 +1,19 @@
 # -*- coding: utf-8 -*-
 
+import re
 from pathlib import Path
 from typing import Dict, List, Union
-import re
 
-from wireviz import __version__, APP_NAME, APP_URL, wv_colors
+from wireviz import APP_NAME, APP_URL, __version__, wv_colors
 from wireviz.DataClasses import Metadata, Options
-from wireviz.wv_helper import flatten2d, open_file_read, open_file_write, smart_file_resolve
 from wireviz.wv_gv_html import html_line_breaks
+from wireviz.wv_helper import (
+    flatten2d,
+    open_file_read,
+    open_file_write,
+    smart_file_resolve,
+)
+
 
 def generate_html_output(filename: Union[str, Path], bom_list: List[List[str]], metadata: Metadata, options: Options):