Python configparser 实战：校验 INI 配置，避开百分号与布尔值陷阱

python3 --version
mkdir ini-task-demo
cd ini-task-demo
cat > task.ini <<'INI'
[task]
name = nightly-100%
enabled = false
interval = 60
INI

"""Validate one small local INI task file without running the task. Python 3.9+."""
import argparse
import configparser
import json
from pathlib import Path
import sys


def load_task(path):
    parser = configparser.ConfigParser(interpolation=None, strict=True)
    with path.open(encoding="utf-8") as stream:
        parser.read_file(stream)
    if parser.defaults():
        raise ValueError("DEFAULT values are not allowed")
    if parser.sections() != ["task"]:
        raise ValueError("expected exactly one [task] section")
    section = parser["task"]
    required = {"name", "enabled", "interval"}
    unknown = set(section) - required
    missing = required - set(section)
    if unknown or missing:
        raise ValueError(
            f"unknown keys: {sorted(unknown)}; missing keys: {sorted(missing)}"
        )
    name = section["name"].strip()
    if not name or "\n" in name or "\r" in name:
        raise ValueError("name must be nonempty and single-line")
    enabled = section.getboolean("enabled")
    interval = section.getint("interval")
    if not 1 <= interval <= 86400:
        raise ValueError("interval must be between 1 and 86400 seconds")
    return {"name": name, "enabled": enabled, "interval": interval}


def main():
    cli = argparse.ArgumentParser(description=__doc__, allow_abbrev=False)
    cli.add_argument("config", type=Path, help="UTF-8 INI file to validate")
    args = cli.parse_args()
    try:
        task = load_task(args.config)
    except (OSError, UnicodeError, configparser.Error, ValueError) as exc:
        print(f"ERROR: {exc}", file=sys.stderr)
        return 1
    print(json.dumps(task, ensure_ascii=False))
    return 0


if __name__ == "__main__":
    raise SystemExit(main())

python3 read_task.py --help
python3 read_task.py task.ini

{"name": "nightly-100%", "enabled": false, "interval": 60}

python3 - <<'PY_CHECK'
import json
import subprocess
import sys
result = subprocess.run(
    [sys.executable, "read_task.py", "task.ini"],
    capture_output=True, text=True, check=False,
)
assert result.returncode == 0, result.stderr
assert result.stderr == ""
assert json.loads(result.stdout) == {
    "name": "nightly-100%", "enabled": False, "interval": 60,
}
print("PASS: literal percent, boolean false, integer interval")
PY_CHECK

python3 - <<'PY_TEST'
from pathlib import Path
import subprocess
import sys

base = Path("task.ini").read_text(encoding="utf-8")
cases = [
    ("duplicate.ini", base + "enabled = true\n", "already exists"),
    ("typo.ini", base.replace("interval =", "intervl ="), "unknown keys"),
    ("boolean.ini", base.replace("false", "maybe"), "Not a boolean"),
    ("range.ini", base.replace("interval = 60", "interval = 0"), "between 1"),
    ("defaults.ini", "[DEFAULT]\nenabled = true\n" + base, "DEFAULT values"),
    ("missing-key.ini", base.replace("enabled = false\n", ""), "missing keys"),
]
for name, text, message in cases:
    path = Path(name)
    path.write_text(text, encoding="utf-8")
    before = path.read_bytes()
    result = subprocess.run(
        [sys.executable, "read_task.py", name],
        capture_output=True, text=True, check=False,
    )
    assert result.returncode == 1, result
    assert result.stdout == "", result.stdout
    assert message in result.stderr, result.stderr
    assert path.read_bytes() == before
    print(f"PASS: {name}")

missing = Path("not-created.ini")
assert not missing.exists()
result = subprocess.run(
    [sys.executable, "read_task.py", str(missing)],
    capture_output=True, text=True, check=False,
)
assert result.returncode == 1 and not result.stdout and result.stderr
assert not missing.exists()
print("PASS: required file missing")
PY_TEST