Helper functions for manipulating Zola content files

zolatoml.py

import sys
import toml
from typing import List, Dict, Any

# I use Zola as my primary static site generator, and these are the functions I
# use regularly with python scripts to access, manipulate, and modify the
# headers and content.


def get_file_metablock_markers(lines: List[str], filename: str) -> List[int]:
    """Return the start and stop of the TOML frontmatter from a Zola file"""
    markers = list(
        map(
            lambda a: a[0],
            filter(lambda l: l[1].strip() == "+++", enumerate(lines)),
        )
    )
    if len(markers) < 2:
        sys.stderr.write(
            "'{}' does not seem to have a metablock".format(filename)
        )
        sys.exit(1)
    return markers


def read_file_metablock(filename: str) -> str:
    """Return the text of a Zola file's TOML frontmatter"""
    with open(filename, "r") as fileobj:
        lines = fileobj.readlines()
        markers = get_file_metablock_markers(lines, filename)
        return "".join(lines[markers[0] + 1 : markers[1]])


def get_file_metablock(filename: str, key=None) -> Dict[str, Any]:
    """Return the frontmatter of a Zola content file as a dictionary

    Zola content uses a TOML block at the top of the file, marked off with three
    plus symbols.  This function returns the contents of that TOML block parsed
    into a dictionary tree.
    """
    try:
        ret = toml.loads(read_file_metablock(filename))
        return ret
    except toml.TomlDecodeError as err:
        print("{} \n at: {}".format(err, filename))
        sys.exit(1)


def get_file_content(filename: str) -> str:
    """Return the markdown content of a Zola content file as an array of lines

    Zola content uses a TOML block at the top of the file, marked off with three
    plus symbols.  This function returns the text content, split by lines, of the markdown.
    """
    with open(filename, "r") as fileobj:
        lines = fileobj.readlines()
        markers = get_file_metablock_markers(lines, filename)
        return lines[markers[1] + 1 :]