How to build your own aerial image Twitter bot

https://gitlab.com/Hannes42/twitter-image-bot

About a year ago I built a small Twitter bot that posts an aerial image of Hamburg, Germany every day.

As I will shut it down (no reason, just decluttering) here’s how it works so you can run your own:

  1. Have aerial images with a permissive license
  2. Register a Twitter account and set it up for posting via API access
  3. Write code to pick an image and post it

Done!

Okok, I am kidding.

I used https://suche.transparenz.hamburg.de/dataset/digitale-orthophotos-belaubt-hamburg3 as data source because they have a CC-BY like license, allowing such a project without any legal complications. As a side benefit these images are already provided in tiles: There is not one big image of the whole region but 1km² image tiles. Perfect for random selection, quick resizing and posting.

Registering a Twitter account and setting it up is a privacy nightmare and, being a good human being as you are, you ought hate any part of it. I followed the Twython tutorial for OAuth1 in a live Python interpreter session which was fairly painless. If you do not want to link a phone number to your Twitter account (see above for how you should feel about that), this approach worked for me in the past but I bet they use regional profiling or worse so your luck might differ.

Next you need some code to do the work for you automatically. Here is what I wrote with Pillow==7.0.0 for the image processing and twython==3.8.2 for posting:

import glob
import random
from io import BytesIO

from PIL import Image
from twython import Twython

## Initialise Twitter
# use a Python interpreter to follow the stops on 
# https://twython.readthedocs.io/en/latest/usage/starting_out.html#oauth-1-user-authentication 
# don't rush, there are some intermediate keys iirc...
APP_KEY = '1234567890ABCDEFGHIJKLMNO'
APP_SECRET = '12345678901234567890123456F8U0CAKATAWAIATATAEARAAA'
OAUTH_TOKEN = '1234567890123456789123456F8U0CAKATAWAIATATAEARAAAA'
OAUTH_TOKEN_SECRET = '123456789012345678901234567890FFSFFSFFSFFSFFS'
twitter = Twython(APP_KEY, APP_SECRET, OAUTH_TOKEN, OAUTH_TOKEN_SECRET)

## Prepare the image
# via https://twython.readthedocs.io/en/latest/usage/advanced_usage.html#posting-a-status-with-an-editing-image

# Pick the image
jpegs = glob.glob("DOP20_HH_sommerbefliegung_2019.zip/*.jpg")
todays_image = random.choice(jpegs)
print(f"Today we will post {todays_image}")
photo = Image.open(todays_image)

# Resize the image
basewidth = 1000
wpercent = (basewidth / float(photo.size[0]))
height = int((float(photo.size[1]) * float(wpercent)))
resized_photo = photo.resize((basewidth, height), Image.ANTIALIAS)

# "Save" the resulting image in temporary memory
stream = BytesIO()
resized_photo.save(stream, format='JPEG')
stream.seek(0)

## We've got what we need, let's tweet
license = "dl-de/by-2-0 (Freie und Hansestadt Hamburg, Landesbetrieb Geoinformation und Vermessung)"
tweet = f"Das ist #IrgendwoInHH, aber wo denn nur?\n\n#codeforhamburg\n\nBild: {license}"

response = twitter.upload_media(media=stream)
twitter.update_status(status=tweet, media_ids=[response['media_id']])

First we initialize that Twython thingie, then we pick a random image from a directory of .jpg files, then we resize it to a maximum of 1000 pixels (you can simplify that if your images are square…) and finally we post it to Twitter.

Set up a cronjob or systemd timer or alarm clock to run the script as often as you like and that’s it.

1 thought on “How to build your own aerial image Twitter bot

  1. Hannes Post author

    Twitter does 4k images nowadays, so you can use 4096 for the basewidth (or just upload your original image, Twitter will resize it for you).

    Reply

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