Search the lemmyverse for the subreddits you are subscribed to on reddit.

reddit_to_lemmy.py

lemmy_communities_url = "https://browse.feddit.de/communities.json?nocache="

import json, urllib.request, time, sys, os

print("H3's Reddit to Lemmy script v0.4.1")

savefile_name = ""
use_savefile = 0
savefile_data = {}

if len(sys.argv) >= 2:
    savefile_name = sys.argv[1]
    if os.path.isfile(savefile_name):
        sf = open(savefile_name,"r")
        savefile_data = json.loads(sf.read())
        use_savefile = 2
        sf.close()
    else:
        use_savefile = 1

if use_savefile == 1:
    print("New savefile " + savefile_name + " will be created on save.") 
elif use_savefile == 2:
    print("Using data from savefile " + savefile_name)
    print("Only new communities will be shown. If you dont want this, don't specify a savefile.")
else:
    print(u"You can specify a save-file with\u001b[1m reddit_to_lemmy.py [filename] \u001b[0m")
    print("This can be used to come back in a few weeks and see what new communities appeared")

subs = []
if use_savefile != 2:
    print()
    print("1. Go to https://www.reddit.com/subreddits/mine")
    print("2. Right-click on \"multireddit of your subscriptions\" in the sidebar, and copy the url.")
    print("3. Paste the URL below")
    multireddit_url = input("Multireddit URL: ")
    print("Parsed subs:",end=" ")
    multireddit_url = multireddit_url[multireddit_url.index("/r/")+3:] #cut out reddit.com url part
    subs = multireddit_url.split("+")
    if use_savefile == 1:
        savefile_data["reddit_subs"] = subs
else:
    subs = savefile_data["reddit_subs"]
    print("Read subs:",end=" ")
print(len(subs))

lemmy_communities_url = lemmy_communities_url + str(int(time.time()))
print("Getting lemmy communities from " + lemmy_communities_url)
communities_json = urllib.request.urlopen(lemmy_communities_url).read()
communities = json.loads(communities_json)

found_by_c = {}
found_by_s = {}
found_total = 0
for c in communities:
    name = c["community"]["name"]
    url = c["url"]
    if not (c["community"]["removed"] or c["community"]["deleted"]):
        if name in subs:
            found_total += 1
            if not name in found_by_c.keys():
                found_by_c[name] = []
            found_by_c[name].append(url)
            if not url in found_by_s.keys():
                found_by_s[url] = []
            found_by_s[url].append(name)

if use_savefile == 2:
    #make copy of old data
    old_c = savefile_data["lemmy_by_c"].copy()
    old_s = savefile_data["lemmy_by_s"].copy()
    old_t = savefile_data["lemmy_total"]
if use_savefile in [1,2]:
    #put new data into savefile dict (only saved on user request) and pointers into shorter variable names
    new_c = savefile_data["lemmy_by_c"] = found_by_c.copy()
    new_s = savefile_data["lemmy_by_s"] = found_by_s.copy()
    savefile_data["lemmy_total"] = found_total
if use_savefile == 2:
    #keep only difference
    for cmn in new_c.keys():
        if cmn in old_c.keys():
            #clear aready known communities
            found_by_c[cmn]=[e for e in found_by_c[cmn] if e not in old_c[cmn]]
            #remove communities that have been cleared fully
            if len(found_by_c[cmn])==0:
                found_by_c.pop(cmn)
    for srv in new_s.keys():
        if srv in old_s.keys():
            #clear already known servers
            found_by_s[srv]=[e for e in found_by_s[srv] if e not in old_s[srv]]
            #remove servers that have been cleared fully
            if len(found_by_s[srv])==0:   
                found_by_s.pop(srv)
    found_total -= savefile_data["lemmy_total"]
    

print("Matched %d unique communities (%d in total) on %d servers." % (len(found_by_c),found_total,len(found_by_s)))

while True:
    print()
    print("How do you want the list grouped?")
    print("1: by community")
    print("2: by server")
    print("3: not at all")
    print("4: save save-file")
    print("other:  quit")
    list_mode = input("Mode (1|2|3|4): ")
    print("\n")
    
    if list_mode=='1':
        for cmn in found_by_c.keys():
            print(cmn+":")
            for srv in found_by_c[cmn]:
                print("\t"+srv)
    elif list_mode=='2':
        for srv in found_by_s.keys():
            print(srv+":")
            for cmn in found_by_s[srv]:
                print("\t"+cmn)
    elif list_mode=='3':
        for cmn in found_by_c.keys():
            for srv in found_by_c[cmn]:
                print(cmn + "@" + srv)
    elif list_mode=='4':
        sf = open(savefile_name, "w")
        sf.write(json.dumps(savefile_data))
        sf.close()
        print("Saved " + savefile_name)
    else:
        quit()