Merge bitcoin/bitcoin#33702: contrib: Remove brittle, confusing and redundant UTF8 encoding from Python IO

fad6118 test: Fix "typo" in written invalid content (MarcoFalke)
fab085c contrib: Use text=True in subprocess over manual encoding handling (MarcoFalke)
fa71c15 scripted-diff: Bump copyright headers after encoding changes (MarcoFalke)
fae6124 contrib: Remove confusing and redundant encoding from IO (MarcoFalke)
fa7d72b lint: Drop check to enforce encoding to be specified in Python scripts (MarcoFalke)
faf39d8 test: Clarify that Python UTF-8 mode is the default today for most systems (MarcoFalke)
fa83e3a lint: Do not allow locale dependent shell scripts (MarcoFalke)

Pull request description:

  Historically, there was an attempt via `test/lint/lint-python-utf8-encoding.py` to enforce explicit UTF8 in every Python IO statement (`open`, `subprocess`, ...). However, the lint check has many problems:

  * The check is incomplete and many IO statements lack the explicit UTF8 specification.
  * It was added at a time when some systems were not UTF8 by default.
  * The check is brittle, as it depends on a fragile regex.

  In theory, now that the minimum Python version is 3.10 (since commit 2123c94), the check could be replaced by `PYTHONWARNDEFAULTENCODING=1` from https://docs.python.org/3/whatsnew/3.10.html#optional-encodingwarning-and-encoding-locale-option. However, this comes with many other problems:

  * All our Python scripts already assume and require UTF8 to be set externally. On almost all modern systems, this is already the default. Some Windows versions do not have UTF8 by default and require `PYTHONUTF8=1` to be set for the tests to run already today (with or without the changes in this pull). Also, the CI and many other Bash scripts force UTF8 via `LC_ALL`. Finally, Python 3.15 will likely enable UTF8 on *all* systems by default, per https://peps.python.org/pep-0686/#abstract.
  * So adding UTF8 to every single IO call is redundant, verbose, and confusing, given that it is the expected default.

  So fix all issues, by:

  * Removing the `test/lint/lint-python-utf8-encoding.py` check.
  * Removing the encoding on the individual IO calls.
  * Clarifying the existing docs around the existing UTF8 requirement and assumption.

  Obviously, every IO call is still free to specify UTF8 or any other encoding explicitly, if there is a documented need for it in the future.

ACKs for top commit:
  theStack:
    re-ACK fad6118
  laanwj:
    Re-ACK fad6118

Tree-SHA512: 78025ea3508597d2299490347614f0ee3e4c66e3ba559ff50e498045a9c8bbd92f3a5ced18719d8fcebbd1e47bdbb56a0c85a5b73b425adb0ea4f02fe69c3149

Author: fanquake

ci/test/02_run_container.py

@@ -26,7 +26,6 @@ def main():
         ["bash", "-c", "grep export ./ci/test/00_setup_env*.sh"],
         stdout=subprocess.PIPE,
         text=True,
-        encoding="utf8",
     ).stdout.splitlines()
     settings = set(l.split("=")[0].split("export ")[1] for l in settings)
     # Add "hidden" settings, which are never exported, manually. Otherwise,
@@ -42,7 +41,7 @@ def main():
         u=os.environ["USER"],
         c=os.environ["CONTAINER_NAME"],
     )
-    with open(env_file, "w", encoding="utf8") as file:
+    with open(env_file, "w") as file:
         for k, v in os.environ.items():
             if k in settings:
                 file.write(f"{k}={v}\n")

contrib/devtools/circular-dependencies.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# Copyright (c) 2018-2020 The Bitcoin Core developers
+# Copyright (c) 2018-present The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -49,7 +49,7 @@ def module_name(path):
 # TODO: implement support for multiple include directories
 for arg in sorted(files.keys()):
     module = files[arg]
-    with open(arg, 'r', encoding="utf8") as f:
+    with open(arg, 'r') as f:
         for line in f:
             match = RE.match(line)
             if match:

contrib/devtools/clang-format-diff.py

@@ -169,7 +169,7 @@ def main():
             sys.exit(p.returncode)
 
         if not args.i:
-            with open(filename, encoding="utf8") as f:
+            with open(filename) as f:
                 code = f.readlines()
             formatted_code = StringIO(stdout).readlines()
             diff = difflib.unified_diff(

contrib/devtools/copyright_header.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# Copyright (c) 2016-2022 The Bitcoin Core developers
+# Copyright (c) 2016-present The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -54,12 +54,12 @@ def applies_to_file(filename):
 GIT_TOPLEVEL_CMD = 'git rev-parse --show-toplevel'.split(' ')
 
 def call_git_ls(base_directory):
-    out = subprocess.check_output([*GIT_LS_CMD, base_directory])
-    return [f for f in out.decode("utf-8").split('\n') if f != '']
+    out = subprocess.check_output([*GIT_LS_CMD, base_directory], text=True)
+    return [f for f in out.split('\n') if f != '']
 
 def call_git_toplevel():
     "Returns the absolute path to the project root"
-    return subprocess.check_output(GIT_TOPLEVEL_CMD).strip().decode("utf-8")
+    return subprocess.check_output(GIT_TOPLEVEL_CMD, text=True).strip()
 
 def get_filenames_to_examine(base_directory):
     "Returns an array of absolute paths to any project files in the base_directory that pass the include/exclude filters"
@@ -140,7 +140,7 @@ def file_has_without_c_style_copyright_for_holder(contents, holder_name):
 ################################################################################
 
 def read_file(filename):
-    return open(filename, 'r', encoding="utf8").read()
+    return open(filename, 'r').read()
 
 def gather_file_info(filename):
     info = {}
@@ -298,8 +298,8 @@ def report_cmd(argv):
 GIT_LOG_CMD = "git log --pretty=format:%%ai %s"
 
 def call_git_log(filename):
-    out = subprocess.check_output((GIT_LOG_CMD % filename).split(' '))
-    return out.decode("utf-8").split('\n')
+    out = subprocess.check_output((GIT_LOG_CMD % filename).split(' '), text=True)
+    return out.split('\n')
 
 def get_git_change_years(filename):
     git_log_lines = call_git_log(filename)
@@ -316,12 +316,12 @@ def get_most_recent_git_change_year(filename):
 ################################################################################
 
 def read_file_lines(filename):
-    with open(filename, 'r', encoding="utf8") as f:
+    with open(filename, 'r') as f:
         file_lines = f.readlines()
     return file_lines
 
 def write_file_lines(filename, file_lines):
-    with open(filename, 'w', encoding="utf8") as f:
+    with open(filename, 'w') as f:
         f.write(''.join(file_lines))
 
 ################################################################################

contrib/filter-lcov.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# Copyright (c) 2017-2020 The Bitcoin Core developers
+# Copyright (c) 2017-present The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -16,8 +16,8 @@
 outfile = args.outfile
 
 in_remove = False
-with open(tracefile, 'r', encoding="utf8") as f:
-    with open(outfile, 'w', encoding="utf8") as wf:
+with open(tracefile, 'r') as f:
+    with open(outfile, 'w') as wf:
         for line in f:
             for p in pattern:
                 if line.startswith("SF:") and p in line:

contrib/linearize/linearize-data.py

@@ -2,7 +2,7 @@
 #
 # linearize-data.py: Construct a linear, no-fork version of the chain.
 #
-# Copyright (c) 2013-2022 The Bitcoin Core developers
+# Copyright (c) 2013-present The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 #
@@ -34,7 +34,7 @@ def get_blk_dt(blk_hdr):
 # When getting the list of block hashes, undo any byte reversals.
 def get_block_hashes(settings):
     blkindex = []
-    with open(settings['hashlist'], "r", encoding="utf8") as f:
+    with open(settings['hashlist'], "r") as f:
         for line in f:
             line = line.rstrip()
             if settings['rev_hash_bytes'] == 'true':
@@ -267,7 +267,7 @@ def run(self):
         print("Usage: linearize-data.py CONFIG-FILE")
         sys.exit(1)
 
-    with open(sys.argv[1], encoding="utf8") as f:
+    with open(sys.argv[1]) as f:
         for line in f:
             # skip comment lines
             m = re.search(r'^\s*#', line)

contrib/linearize/linearize-hashes.py

@@ -2,7 +2,7 @@
 #
 # linearize-hashes.py:  List blocks in a linear, no-fork version of the chain.
 #
-# Copyright (c) 2013-2022 The Bitcoin Core developers
+# Copyright (c) 2013-present The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 #
@@ -87,7 +87,7 @@ def get_block_hashes(settings, max_blocks_per_call=10000):
 
 def get_rpc_cookie():
     # Open the cookie file
-    with open(os.path.join(os.path.expanduser(settings['datadir']), '.cookie'), 'r', encoding="ascii") as f:
+    with open(os.path.join(os.path.expanduser(settings['datadir']), '.cookie'), 'r') as f:
         combined = f.readline()
         combined_split = combined.split(":")
         settings['rpcuser'] = combined_split[0]
@@ -98,7 +98,7 @@ def get_rpc_cookie():
         print("Usage: linearize-hashes.py CONFIG-FILE")
         sys.exit(1)
 
-    with open(sys.argv[1], encoding="utf8") as f:
+    with open(sys.argv[1]) as f:
         for line in f:
             # skip comment lines
             m = re.search(r'^\s*#', line)

contrib/message-capture/message-capture-parser.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# Copyright (c) 2020-2022 The Bitcoin Core developers
+# Copyright (c) 2020-present The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Parse message capture binary files.  To be used in conjunction with -capturemessages."""
@@ -205,7 +205,7 @@ def main():
 
     jsonrep = json.dumps(messages)
     if output:
-        with open(str(output), 'w+', encoding="utf8") as f_out:
+        with open(str(output), 'w+') as f_out:
             f_out.write(jsonrep)
     else:
         print(jsonrep)

contrib/seeds/generate-seeds.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# Copyright (c) 2014-2021 The Bitcoin Core developers
+# Copyright (c) 2014-present The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 '''
@@ -168,16 +168,16 @@ def main():
     g.write(' *\n')
     g.write(' * Each line contains a BIP155 serialized (networkID, addr, port) tuple.\n')
     g.write(' */\n')
-    with open(os.path.join(indir,'nodes_main.txt'), 'r', encoding="utf8") as f:
+    with open(os.path.join(indir,'nodes_main.txt'), 'r') as f:
         process_nodes(g, f, 'chainparams_seed_main')
     g.write('\n')
-    with open(os.path.join(indir,'nodes_signet.txt'), 'r', encoding="utf8") as f:
+    with open(os.path.join(indir,'nodes_signet.txt'), 'r') as f:
         process_nodes(g, f, 'chainparams_seed_signet')
     g.write('\n')
-    with open(os.path.join(indir,'nodes_test.txt'), 'r', encoding="utf8") as f:
+    with open(os.path.join(indir,'nodes_test.txt'), 'r') as f:
         process_nodes(g, f, 'chainparams_seed_test')
     g.write('\n')
-    with open(os.path.join(indir,'nodes_testnet4.txt'), 'r', encoding="utf8") as f:
+    with open(os.path.join(indir,'nodes_testnet4.txt'), 'r') as f:
         process_nodes(g, f, 'chainparams_seed_testnet4')
     g.write('#endif // BITCOIN_CHAINPARAMSSEEDS_H\n')
 

contrib/seeds/makeseeds.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# Copyright (c) 2013-2022 The Bitcoin Core developers
+# Copyright (c) 2013-present The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 #
@@ -211,7 +211,7 @@ def main():
     print('Done.', file=sys.stderr)
 
     print('Loading and parsing DNS seeds…', end='', file=sys.stderr, flush=True)
-    with open(args.seeds, 'r', encoding='utf8') as f:
+    with open(args.seeds, 'r') as f:
         lines = f.readlines()
     ips = [parseline(line) for line in lines]
     random.shuffle(ips)