A little Python script to fetch all of a person's Mastodon followers and followings and see which servers they're on

get_mastodon_servers.py

#!/usr/bin/env python3
import requests
import requests_cache
import json

requests_cache.install_cache('masto_cache')
MASTODON_USERNAME = "sil@mastodon.social"

def fetch(endpoint):
    url = f"https://{server}/api/v1/accounts/{account_id}/{endpoint}"
    peeps = []
    while True:
        print("get url", url)
        response = requests.get(url)
        j = response.json()
        if len(j) == 0: break
        addresses = [x["acct"] for x in j]
        naddresses = []
        for address in addresses:
            naddresses.append(f"{address}@{server}" if "@" not in address else address)
        peeps += naddresses
        link = response.headers["Link"].split(", ")
        first_url, first_rel = link[0].split("; ")
        if len(link) == 1:
            break
        else:
            second_url, second_rel = link[1].split("; ")
        if "next" in first_rel: url = first_url.strip()[1:-1]
        elif "next" in second_rel: url = second_url.strip()[1:-1]
        else:
            raise Exception(f"Didn't understand Link header: {response.headers['Link']}")
    return peeps


server = MASTODON_USERNAME.split("@")[1]
user_account_url = f"https://{server}/api/v1/accounts/lookup?acct={MASTODON_USERNAME}"
account_id = requests.get(user_account_url).json()["id"]

followers = fetch("followers")
following = fetch("following")

servers = {}
for f in followers + following:
    name, s = f.split("@")
    if s not in servers: servers[s] = 0
    servers[s] += 1

print(sorted(servers.items(), key=lambda x:x[1]))