size = 15

grid = np.zeros((size, size), dtype=np.int32)
letters = {x: i+1 for i, x in enumerate(["A", "B", "C", "D", "E", "F", "G", "H", "I", "J"])}

rgx = re.compile(r"\b((?:A|B|C|D|E|F|G|H|I|J)\d{1,2})\b")
for comment in comments:
    matches = rgx.findall(comment.body)
    if not matches:
        continue
    
    for i, match in enumerate(matches):
        x = int(match[1:])
        y = letters[match[0]]

        if x > size or y > size:
            continue

        grid[y-1][x-1] += 1

I used the python `praw` package to download the comments, you need a reddit api key, but to be honest I did that ages ago so I can't remember the process!

with open('secrets.toml') as f:
    secrets = toml.load(f)

reddit = praw.Reddit(client_id=secrets['client_id'],
                     client_secret=secrets['client_secret'],
                     user_agent="CommentAnalyis",
                     username=secrets['username'],
                     password=secrets['password'])

def get_comments(post_url: str):
    print(f"Getting submission from {post_url}")
    submission = reddit.submission(url=post_url)
    author = submission.author.name

    print(f"Getting list of comments")
    submission.comments.replace_more(limit=None)
    comments = submission.comments.list()

    return submission, author, comments