Girl’s Markdown

girlmarkdown.py

import sys

# `pip install Markdown`
from markdown import markdown

FLOWER = '🌸'
START_PINK = '<span style="color: pink">'
END_PINK   = '</span>'

def girlmarkdown(text):
    md = markdown(text)
    # we actually grab all the points with flowers in them and then reassemble
    # the output string to avoid quadratic string-concatenation times
    splice_points = []
    for i, c in enumerate(md):
        if c == FLOWER:
            splice_points.append(i)

    if len(splice_points) % 2 == 1:
        raise ValueError('Unmatched flowers')

    # replacing flowers with START_PINK and END_PINK
    parts = []
    before = 0
    end = -1
    itr = iter(splice_points)
    for start in itr:
        end = next(itr)
        parts.append(md[before:start])
        parts.append(START_PINK)
        parts.append(md[start + 1:end])
        parts.append(END_PINK)
    # make sure to not leave out the chunk of text after the last flower
    parts.append(md[end + 1:])
    return ''.join(parts)

def main():
    for filename in sys.argv[1:]:
        with open(filename, encoding='utf-8') as f:
            print(girlmarkdown(f.read()))

if __name__ == '__main__':
    main()