Merge bitcoin/bitcoin#24766: lint: convert spellchecking lint test to python

4685463 doc: Update lint test docs (Fabian Jahr)
77f98df lint: convert spell check lint test to python (Fabian Jahr)

Pull request description:

  The new python version should produce the exact same output as the bash version but be easier to maintain.

ACKs for top commit:
  MarcoFalke:
    cr ACK 4685463

Tree-SHA512: 242b802b750b42b299b93d1de4bcf17d92ad0a633d31894145d8590782a1db1041de59a283f133a4f75898d95444eb3c842005a6aa5cb919543625addad596d8

Author: MarcoFalke

test/README.md

@@ -310,7 +310,7 @@ Use the `-v` option for verbose output.
 | [`lint-python.sh`](lint/lint-python.sh) | [pyzmq](https://github.com/zeromq/pyzmq)
 | [`lint-python-dead-code.py`](lint/lint-python-dead-code.py) | [vulture](https://github.com/jendrikseipp/vulture)
 | [`lint-shell.sh`](lint/lint-shell.sh) | [ShellCheck](https://github.com/koalaman/shellcheck)
-| [`lint-spelling.sh`](lint/lint-spelling.sh) | [codespell](https://github.com/codespell-project/codespell)
+| [`lint-spelling.py`](lint/lint-spelling.py) | [codespell](https://github.com/codespell-project/codespell)
 
 In use versions and install instructions are available in the [CI setup](../ci/lint/04_install.sh).
 
@@ -321,7 +321,7 @@ Please be aware that on Linux distributions all dependencies are usually availab
 Individual tests can be run by directly calling the test script, e.g.:
 
 ```
-test/lint/lint-files.sh
+test/lint/lint-files.py
 ```
 
 You can run all the shell-based lint tests by running:

test/lint/lint-spelling.py

@@ -0,0 +1,40 @@
+#!/usr/bin/env python3
+#
+# Copyright (c) 2022 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+"""
+Warn in case of spelling errors.
+Note: Will exit successfully regardless of spelling errors.
+"""
+
+from subprocess import check_output, STDOUT, CalledProcessError
+
+IGNORE_WORDS_FILE = 'test/lint/spelling.ignore-words.txt'
+FILES_ARGS = ['git', 'ls-files', '--', ":(exclude)build-aux/m4/", ":(exclude)contrib/seeds/*.txt", ":(exclude)depends/", ":(exclude)doc/release-notes/", ":(exclude)src/leveldb/", ":(exclude)src/crc32c/", ":(exclude)src/qt/locale/", ":(exclude)src/qt/*.qrc", ":(exclude)src/secp256k1/", ":(exclude)src/minisketch/", ":(exclude)src/univalue/", ":(exclude)contrib/builder-keys/keys.txt", ":(exclude)contrib/guix/patches"]
+
+
+def check_codespell_install():
+    try:
+        check_output(["codespell", "--version"])
+    except FileNotFoundError:
+        print("Skipping spell check linting since codespell is not installed.")
+        exit(0)
+
+
+def main():
+    check_codespell_install()
+
+    files = check_output(FILES_ARGS).decode("utf-8").splitlines()
+    codespell_args = ['codespell', '--check-filenames', '--disable-colors', '--quiet-level=7', '--ignore-words={}'.format(IGNORE_WORDS_FILE)] + files
+
+    try:
+        check_output(codespell_args, stderr=STDOUT)
+    except CalledProcessError as e:
+        print(e.output.decode("utf-8"), end="")
+        print('^ Warning: codespell identified likely spelling errors. Any false positives? Add them to the list of ignored words in {}'.format(IGNORE_WORDS_FILE))
+
+
+if __name__ == "__main__":
+    main()