download_all_emoji.py

# download_all_emoji.py: A script to query the slack API for all emojis on a 
# given instance, and then download them into an "emojis" folder
#
# USAGE
#
#   first, set a `SLACK_TOKEN` environment variable to a token that has 
#   `emoji:read` permission. Then, run this script with 
#   `python download_all_emoji.py`.
#
#   it does not run in parallel, so it may take a while. Are you really
#   that busy that you need to get it done in a hurry?
import json
import os
import requests
import subprocess

if not os.path.isfile("res.json"):
    url = "https://slack.com/api/emoji.list"
    res = requests.get(
        url, headers={"Authorization": f'Bearer {os.environ["SLACK_TOKEN"]}'}
    )
    assert res.status_code == 200
    emoji = res.json()["emoji"]
    with open("res.json", "w") as out:
        json.dump(emoji, out, indent=4)
else:
    emoji = json.load(open("res.json"))

if not os.path.isdir("emoji"):
    os.mkdir("emoji")

for name, val in emoji.items():
    if val.startswith("alias:"):
        try:
            url = emoji[val[6:]]
        except KeyError:
            # seems like some of these are aliases to standard emoji, and are
            # not associated with a custom URL. proceed without downloading.
            continue
    else:
        url = val

    extension = os.path.splitext(url)[1]
    assert extension
    # no-clobber means don't download if we already have it
    cmd = f'wget --no-clobber -O "emoji/{name}{extension}" "{url}"'
    print(cmd)
    subprocess.run(cmd, shell=True)