Update flake8 config (#1749)

.pre-commit-config.yaml

@@ -48,16 +48,16 @@ repos:
       - id: doc8
         args: [--max-line-length=200]
 
-  # - repo: https://github.com/pycqa/flake8
-  #   rev: 4.0.1
-  #   hooks:
-  #     - id: flake8
-  #       additional_dependencies:
-  #         [
-  #           "flake8-bugbear==20.1.4",
-  #           "flake8-logging-format==0.6.0",
-  #           "flake8-implicit-str-concat==0.2.0",
-  #         ]
+  - repo: https://github.com/pycqa/flake8
+    rev: 4.0.1
+    hooks:
+      - id: flake8
+        additional_dependencies:
+          [
+            "flake8-bugbear==20.1.4",
+            "flake8-logging-format==0.6.0",
+            "flake8-implicit-str-concat==0.2.0",
+          ]
 
   - repo: https://github.com/sirosen/check-jsonschema
     rev: 0.14.1

docs/source/conf.py

@@ -240,16 +240,7 @@
 
 # -- Options for LaTeX output ---------------------------------------------
 
-latex_elements = {
-    # The paper size ('letterpaper' or 'a4paper').
-    #'papersize': 'letterpaper',
-    # The font size ('10pt', '11pt' or '12pt').
-    #'pointsize': '10pt',
-    # Additional stuff for the LaTeX preamble.
-    #'preamble': '',
-    # Latex figure (float) alignment
-    #'figure_align': 'htbp',
-}
+latex_elements = {}
 
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title,

nbconvert/exporters/base.py

@@ -87,7 +87,7 @@ def export(exporter, nb, **kw):
     return output, resources
 
 
-def get_exporter(name, config=get_config()):
+def get_exporter(name, config=get_config()):  # noqa
     """Given an exporter name or import path, return a class ready to be instantiated
 
     Raises ExporterName if exporter is not found or ExporterDisabledError if not enabled
@@ -130,7 +130,7 @@ def get_exporter(name, config=get_config()):
     )
 
 
-def get_export_names(config=get_config()):
+def get_export_names(config=get_config()):  # noqa
     """Return a list of the currently supported export targets
 
     Exporters can be found in external packages by registering

nbconvert/exporters/exporter.py

@@ -9,7 +9,6 @@
 import collections
 import copy
 import datetime
-import io
 import os
 import sys
 from typing import Optional
@@ -171,7 +170,7 @@ def from_filename(self, filename: str, resources: Optional[dict] = None, **kw):
         # Pull the metadata from the filesystem.
         if resources is None:
             resources = ResourcesDict()
-        if not "metadata" in resources or resources["metadata"] == "":
+        if "metadata" not in resources or resources["metadata"] == "":
             resources["metadata"] = ResourcesDict()
         path, basename = os.path.split(filename)
         notebook_name = os.path.splitext(basename)[0]
@@ -239,7 +238,7 @@ def register_preprocessor(self, preprocessor, enabled=False):
             preprocessor_cls = import_item(preprocessor)
             return self.register_preprocessor(preprocessor_cls, enabled)
 
-        if constructed and hasattr(preprocessor, "__call__"):
+        if constructed and hasattr(preprocessor, "__call__"):  # noqa
             # Preprocessor is a function, no need to construct it.
             # Register and return the preprocessor.
             if enabled:

nbconvert/exporters/pdf.py

@@ -8,7 +8,6 @@
 import subprocess
 import sys
 from tempfile import TemporaryDirectory
-from typing import Optional
 
 from traitlets import Bool, Instance, Integer, List, Unicode, default
 
@@ -128,7 +127,7 @@ def run_command(self, command_list, filename, count, log_function, raise_on_fail
 
         with open(os.devnull, "rb") as null:
             stdout = subprocess.PIPE if not self.verbose else None
-            for index in range(count):
+            for _ in range(count):
                 p = subprocess.Popen(
                     command,
                     stdout=stdout,

nbconvert/exporters/templateexporter.py

@@ -425,7 +425,7 @@ def _register_filter(self, environ, name, jinja_filter):
             filter_cls = import_item(jinja_filter)
             return self._register_filter(environ, name, filter_cls)
 
-        if constructed and hasattr(jinja_filter, "__call__"):
+        if constructed and hasattr(jinja_filter, "__call__"):  # noqa
             # filter is a function, no need to construct it.
             environ.filters[name] = jinja_filter
             return jinja_filter
@@ -510,7 +510,7 @@ def _init_preprocessors(self):
         #  * We rely on recursive_update, which can only merge dicts, lists will be overwritten
         #  * We can use the key with numerical prefixing to guarantee ordering (/etc/*.d/XY-file style)
         #  * We can disable preprocessors by overwriting the value with None
-        for key, preprocessor in sorted(preprocessors.items(), key=lambda x: x[0]):
+        for _, preprocessor in sorted(preprocessors.items(), key=lambda x: x[0]):
             if preprocessor is not None:
                 kwargs = preprocessor.copy()
                 preprocessor_cls = kwargs.pop("type")

nbconvert/exporters/tests/test_exporter.py

@@ -19,7 +19,7 @@
 from traitlets.config import Config
 
 from ...preprocessors.base import Preprocessor
-from ..base import ExporterDisabledError, get_export_names
+from ..base import get_export_names
 from ..exporter import Exporter
 from .base import ExportersTestsBase
 
@@ -58,12 +58,6 @@ def test_preprocessor(self):
         (notebook, resources) = exporter.from_filename(self._get_notebook())
         self.assertEqual(notebook["pizza"], "cheese")
 
-    def test_get_export_names_disable(self):
-        """Can we disable a specific importer?"""
-        config = Config({"Exporter": {"enabled": False}})
-        export_names = get_export_names()
-        self.assertFalse("Exporter" in export_names)
-
     def test_get_export_names_disable(self):
         """Can we disable all exporters then enable a single one"""
         config = Config({"Exporter": {"enabled": False}, "NotebookExporter": {"enabled": True}})

nbconvert/exporters/tests/test_html.py

@@ -47,22 +47,6 @@ def test_export_notebook(self):
         (output, resources) = HTMLExporter(template_name="lab").from_filename(self._get_notebook())
         assert len(output) > 0
 
-    def test_prompt_number(self):
-        """
-        Does HTMLExporter properly format input and output prompts?
-        """
-        (output, resources) = HTMLExporter(template_name="lab").from_filename(
-            self._get_notebook(nb_name="prompt_numbers.ipynb")
-        )
-        in_regex = r"In \[(.*)\]:"
-        out_regex = r"Out\[(.*)\]:"
-
-        ins = ["2", "10", " ", " ", "0"]
-        outs = ["10"]
-
-        assert re.findall(in_regex, output) == ins
-        assert re.findall(out_regex, output) == outs
-
     def test_prompt_number(self):
         """
         Does HTMLExporter properly format input and output prompts?

nbconvert/exporters/tests/test_pdf.py

@@ -3,7 +3,6 @@
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
-import logging
 import os
 import shutil
 from tempfile import TemporaryDirectory

nbconvert/exporters/tests/test_rst.py

@@ -3,11 +3,9 @@
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
-import io
 import re
 
 import nbformat
-import pytest
 from nbformat import v4
 
 from ...tests.utils import onlyif_cmds_exist

nbconvert/exporters/tests/test_webpdf.py

@@ -3,7 +3,6 @@
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
-import io
 from unittest.mock import patch
 
 import pytest

nbconvert/filters/citation.py

@@ -78,7 +78,7 @@ def get_offset(self):
         # Compute startposition in source
         lin, offset = self.getpos()
         pos = 0
-        for i in range(lin - 1):
+        for _ in range(lin - 1):
             pos = self.data.find("\n", pos) + 1
         return pos + offset
 

nbconvert/filters/highlight.py

@@ -121,7 +121,7 @@ def __call__(self, source, language=None, metadata=None, strip_verbatim=False):
             source, LatexFormatter(**self.extra_formatter_options), language, metadata
         )
         if strip_verbatim:
-            latex = latex.replace(r"\begin{Verbatim}[commandchars=\\\{\}]" + "\n", "")
+            latex = latex.replace(r"\begin{Verbatim}[commandchars=\\\{\}]" + "\n", "")  # noqa
             return latex.replace("\n\\end{Verbatim}\n", "")
         else:
             return latex

nbconvert/filters/tests/test_highlight.py

@@ -16,8 +16,6 @@
 
 import xml
 
-from traitlets.config import Config
-
 from ...tests.base import TestsBase
 from ..highlight import Highlight2HTML, Highlight2Latex
 

nbconvert/filters/tests/test_markdown.py

@@ -122,15 +122,15 @@ def test_markdown2html_math(self):
         # all the "<", ">", "&" must be escaped correctly
         cases = [
             (
-                "\\begin{equation*}\n"
+                "\\begin{equation*}\n"  # noqa
                 + (
                     "\\left( \\sum_{k=1}^n a_k b_k \\right)^2 "
                     "\\leq \\left( \\sum_{k=1}^n a_k^2 \\right) "
                     "\\left( \\sum_{k=1}^n b_k^2 \\right)\n"
                 )
                 + "\\end{equation*}"
             ),
-            ("$$\n" "a = 1 *3* 5\n" "$$"),
+            ("$$\na = 1 *3* 5\n$$"),
             "$ a = 1 *3* 5 $",
             "$s_i = s_{i}\n$",
             "$a<b&b<lt$",
@@ -139,7 +139,7 @@ def test_markdown2html_math(self):
             "$$a<b&b<lt$$",
             "$$a<b&lt;b>a;a-b<0$$",
             "$$<k'>$$",
-            ("$$x\n" "=\n" "2$$"),
+            ("$$x\n=\n2$$"),
             (
                 "$$\n"
                 "b =  \\left[\n"
@@ -148,7 +148,7 @@ def test_markdown2html_math(self):
                 "\\right]\n"
                 "$$"
             ),
-            ("\\begin{equation*}\n" "x = 2 *55* 7\n" "\\end{equation*}"),
+            ("\\begin{equation*}\nx = 2 *55* 7\n\\end{equation*}"),
             """$
 \\begin{tabular}{ l c r }
   1 & 2 & 3 \\

nbconvert/filters/tests/test_metadata.py

@@ -14,7 +14,7 @@ def test_get_metadata():
     }
     assert get_metadata(output, "nowhere") is None
     assert get_metadata(output, "height") == 2
-    assert get_metadata(output, "unconfined") == None
-    assert get_metadata(output, "unconfined", "image/png") == True
+    assert get_metadata(output, "unconfined") is None
+    assert get_metadata(output, "unconfined", "image/png") is True
     assert get_metadata(output, "width", "image/png") == 1
     assert get_metadata(output, "height", "image/png") == 3

nbconvert/nbconvertapp.py

@@ -391,7 +391,7 @@ def init_notebooks(self):
                 self.log.warning("pattern %r matched no files", pattern)
 
             for filename in globbed_files:
-                if not filename in filenames:
+                if filename not in filenames:
                     filenames.append(filename)
         self.notebooks = filenames
 

nbconvert/postprocessors/serve.py

@@ -95,7 +95,7 @@ def postprocess(self, input):
         if self.open_in_browser:
             try:
                 browser = webbrowser.get(self.browser or None)
-                b = lambda: browser.open(url, new=2)
+                b = lambda: browser.open(url, new=2)  # noqa
                 threading.Thread(target=b).start()
             except webbrowser.Error as e:
                 self.log.warning("No web browser found: %s." % e)

nbconvert/postprocessors/tests/test_serve.py

@@ -19,6 +19,6 @@ def test_constructor(self):
         try:
             from ..serve import ServePostProcessor
         except ImportError:
-            print("Something weird is happening.\n" "Tornado is sometimes present, sometimes not.")
+            print("Something weird is happening.\nTornado is sometimes present, sometimes not.")
             raise
         ServePostProcessor()

nbconvert/preprocessors/clearmetadata.py

@@ -15,15 +15,11 @@ class ClearMetadataPreprocessor(Preprocessor):
 
     clear_cell_metadata = Bool(
         True,
-        help=(
-            "Flag to choose if cell metadata is to be cleared " "in addition to notebook metadata."
-        ),
+        help=("Flag to choose if cell metadata is to be cleared in addition to notebook metadata."),
     ).tag(config=True)
     clear_notebook_metadata = Bool(
         True,
-        help=(
-            "Flag to choose if notebook metadata is to be cleared " "in addition to cell metadata."
-        ),
+        help=("Flag to choose if notebook metadata is to be cleared in addition to cell metadata."),
     ).tag(config=True)
     preserve_nb_metadata_mask = Set(
         [("language_info", "name")],

nbconvert/preprocessors/csshtmlheader.py

@@ -5,15 +5,12 @@
 # Distributed under the terms of the Modified BSD License.
 
 import hashlib
-import io
 import os
 
 from jupyterlab_pygments import JupyterStyle
 from pygments.style import Style
 from traitlets import Type, Unicode, Union
 
-import nbconvert.resources
-
 from .base import Preprocessor
 
 try:

nbconvert/preprocessors/execute.py

@@ -5,7 +5,7 @@
 from nbclient import execute as _execute
 
 # Backwards compatability for imported name
-from nbclient.exceptions import CellExecutionError
+from nbclient.exceptions import CellExecutionError  # noqa
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.

nbconvert/preprocessors/sanitize.py

@@ -26,7 +26,7 @@ class SanitizeHTML(Preprocessor):
         Unicode(),
         config=True,
         default_value=ALLOWED_STYLES,
-        help="Allowed CSS styles if <style> tag is whitelisted",
+        help="Allowed CSS styles if <style> tag is allowed",
     )
     strip = Bool(
         config=True,

nbconvert/preprocessors/svg2pdf.py

@@ -6,7 +6,6 @@
 # Distributed under the terms of the Modified BSD License.
 
 import base64
-import io
 import os
 import subprocess
 import sys

nbconvert/preprocessors/tests/test_regexremove.py

@@ -7,7 +7,6 @@
 
 import re
 
-from nbformat import from_dict
 from nbformat import v4 as nbformat
 
 from ..regexremove import RegexRemovePreprocessor