add delete_section

    2023-12-10, Bo Zhang, created

    2023-12-15, Bo Zhang, added verify_checksum and append_header, add module header

    2023-12-16, Bo Zhang, fixed a bug in finding the first key when reformatting

    2024-06-08, Bo Zhang, added delete_section

"""

import bisect

import warnings

from copy import deepcopy

from typing import Optional

    h_copy.add_comment(comment, before=first_key)

    h_copy.add_comment("=" * 72, before=first_key)

    return h_copy

def delete_section(

    header: fits.Header,

    title="WORLD COORDINATE SYSTEM INFORMATION",

) -> fits.Header:

    """

    Delete a section from a fits header.

    This function is used to delete the section of WCS information from the header.

    Parameters

    ----------

    header: fits.Header

        Header.

    title: str

        Title of the section to be deleted.

    Returns

    -------

    fits.Header

        Edited header.

    """

    # find sep lines

    i_seps = []

    for i_card, card in enumerate(header.cards):

        if (

            card.keyword == "COMMENT"

            and isinstance(card.value, str)

            and card.value.startswith("===")

        ) or i_card == len(header.cards) - 1:

            i_seps.append(i_card)

    # find section title

    i_section = -1

    for i_card, card in enumerate(header.cards):

        if card.keyword == "COMMENT" and card.value == title:

            i_section = i_card

            break

    if i_section < 0:

        raise ValueError(f"Title not found: `{title}`")

    # find section start and stop

    idx = bisect.bisect(i_seps, i_section)

    i_section_start = i_seps[idx - 1]

    i_section_stop = i_seps[idx + 1]

    # delete keys in reverse order

    print(f"Delete keys {i_section_start} to {i_section_stop} ...")

    for i in range(i_section_stop - 1, i_section_start - 1, -1):

        del header[i]

    return header