Given a FOLDER, replicate all markdown files with pelican metadata converted to pandoc YAML metadata in `new-FOLDER`

pel2pan.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# DESCRIPTION
# (c) Copyright 2020 by Joseph Reagle
# Licensed under the GPLv3, see <http://www.gnu.org/licenses/gpl-3.0.html>
#

import argparse  # http://docs.python.org/dev/library/argparse.html
import codecs
import logging
import os
import sys
from pathlib import Path, PurePath

import yaml

HOME = str(Path("~").expanduser())

exception = logging.exception
critical = logging.critical
error = logging.error
warning = logging.warning
info = logging.info
debug = logging.debug

AUTHOR = "Joseph Reagle"  # default author if not provided


def main(argv):
    """Process arguments"""
    arg_parser = argparse.ArgumentParser(
        description="Given a FOLDER, replicate all markdown files with pelican metadata converted to pandoc YAML metadata in `new-FOLDER`"
    )

    # positional arguments
    arg_parser.add_argument("folder", nargs=1, metavar="FOLDER")
    # optional arguments
    arg_parser.add_argument(
        "-s",
        "--short",
        action="store_true",
        default=False,
        help="create short entries of metadata only (for testing)",
    )
    arg_parser.add_argument(
        "-L",
        "--log-to-file",
        action="store_true",
        default=False,
        help="log to file %(prog)s.log",
    )
    arg_parser.add_argument(
        "-V",
        "--verbose",
        action="count",
        default=0,
        help="increase verbosity (specify multiple times for more)",
    )
    arg_parser.add_argument("--version", action="version", version="0.5")
    args = arg_parser.parse_args(argv)

    log_level = logging.ERROR  # 40

    if args.verbose == 1:
        log_level = logging.WARNING  # 30
    elif args.verbose == 2:
        log_level = logging.INFO  # 20
    elif args.verbose >= 3:
        log_level = logging.DEBUG  # 10
    LOG_FORMAT = "%(levelname).3s %(funcName).5s: %(message)s"
    if args.log_to_file:
        print("logging to file")
        logging.basicConfig(
            filename=f"{str(PurePath(__file__).name)}.log",
            filemode="w",
            level=log_level,
            format=LOG_FORMAT,
        )
    else:
        logging.basicConfig(level=log_level, format=LOG_FORMAT)

    return args


def process_folder(args):
    info(f"{args.folder[0]=}")
    for path, dirs, filenames in os.walk(args.folder[0]):
        for filename in filenames:
            # BUG?: would there be non-markdown files to replicate?
            # BUG?: does pelican support file extensions beyond ".md"?
            if not filename.endswith((".md", ".markdown")):
                error(f"skipping {filename=}")
                continue
            filename_full = f"{path}/{filename}"
            path_new = f"new-{path}"
            filename_new_full = f"{path_new}/{filename}"
            info(f"processing {filename_full=}")
            with open(filename_full, "r") as fn:
                content = fn.read()
                if content[0] == codecs.BOM_UTF8.decode("utf8"):
                    content = content[1:]
                content = content.split("\n")
                debug(f"{content=}")
                content_new = []
                metadata = {}
                metadata_new = []
                for index, line in enumerate(content):
                    debug(f"{index=}{line=}")
                    if ":" in line:
                        key, value = line.split(":", 1)
                        if value.strip():
                            metadata[key.strip().lower()] = value.strip()
                    else:
                        break
                if not "author" in metadata:
                    metadata["author"] = AUTHOR

                info(f"---\n{yaml.dump(metadata)}...\n")
                content_new.append(f"---\n{yaml.dump(metadata)}...\n")
                if not args.short:
                    debug("".join(content[index:]))
                    content_new.append("\n".join(content[index:]))
                info(f"{path_new=}")
                os.makedirs(path_new, exist_ok=True)
                with open(filename_new_full, "w") as fn_new:
                    fn_new.write("".join(content_new))


if __name__ == "__main__":
    args = main(sys.argv[1:])
    process_folder(args)