Save in a CSV file threads with their comments, and associated data, of a Facebook group (even closed groups where you are not an admin but a member).
Just download the file fb_group_scraper.py and run the script:
$ python fb_group_scraper.py <group_id> <access_token> [max_threads]You usually can find the group ID looking on your browser. If you access to the chosen group, you will see a URL like https://www.facebook.com/groups/1234567890, where the group ID is 1234567890. In the case of there is no number, try with a tool like Lookup-ID.com.
Moreover, you will need an access token to use this script. Go to the Graph API Explorer and get a User Access Token. Pay attention to select the version 2.3, because is the last one that allows get data from a closed group if you are only a member. Select the user_groups option and click on the Get Access Token button. Then you can see a long alphanumeric word, which will be your token.
This is an optional argument that limits the amount of threads you can scrape. Note that if there are a lot of posts in the group, the script will require a fairly long time.