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PY: Get Post Details

Get post details from list of posts from the blockchain with created filter and tag then display selected post details.

Full, runnable src of Get Post Details can be downloaded as part of the PY tutorials repository.

We will explain and show you how to access the Crea blockchain using the crea-python library to fetch list of posts filtered by a filter and tag

Intro

Crea python library has built-in function to get details of post with author and permlink as an argument. Since we don’t have predefined post or author/permlink. We will fetch post list from previous tutorial and give option to choose one option/post to get its details. get_content function fetches latest state of the post and delivers its details. Note that get_discussions_by_now filter is used for fetching 5 posts which by default contains details of each post, but for purpose of this tutorial we will showcase get_content function to fetch details.

Steps

  1. App setup - Library install and import
  2. Post list - List of posts to select from created filter
  3. Post details - Get post details for selected post
  4. Print output - Print results in output

1. App setup

In this tutorial we use 3 packages, pick - helps us to select filter interactively. crea - crea-python library, interaction with Blockchain. pprint - print results in better format.

First we import all three library and initialize Crea class

    import pprint
    from pick import pick
    # initialize Crea class
    from crea import Crea

    s = Crea()

2. Post list

Next we will fetch and make list of posts and setup pick properly.

    query = {
        "limit":5, #number of posts
        "tag":"" #tag of posts
        }
    #post list for selected query
    posts = s.get_discussions_by_now(query)

    title = 'Please choose post: '
    options = []
    #posts list options
    for post in posts:
        options.append(post["author"]+'/'+post["permlink"])
    # get index and selected filter name
    option, index = pick(options, title)

This will show us list of posts to select in terminal/command prompt. And after selection we will get index and post name to index and option variables.

3. Post details

Next we will fetch post details with get_content. By default get_discussions_by_now function already contains post details, but for this tutorial purpose we will ignore all other fields but only use author and permlink fields to fetch fresh post details.


details = s.get_content(posts[index]["author"],posts[index]["permlink"])

4. Print output

Next, we will print result, details of selected post.

    # print post details for selected post
    pprint.pprint(details)
    pprint.pprint("Selected: "+option)

The example of result returned from the service is a JSON object with the following properties:

{
    "id": 37338948,
    "author": "crearyblog",
    "permlink": "join-team-creary-at-tokenfest",
    "category": "creary",
    "parent_author": "",
    "parent_permlink": "creary",
    "title": "Join Team Creary at TokenFest!",
    "body":
        "<a href=\"https://tokenfest.adria.digital\"><img src=\"https://i.imgur.com/fOScDIW.png\"/></a>\n\nHello Crearians! If you’d like to meet Team Creary live-in-person, or are just interested in attending what promises to be a great blockchain conference, join us at <a href=\"https://tokenfest.adria.digital/\">TokenFest</a> in San Francisco from March 15th to 16th. \n\nCreary CEO, Ned Scott, will be participating in a fireside chat alongside Creary’s CTO, Harry Schmidt, as well as the creator of Utopian.io, Diego Pucci. Creary will also be hosting the opening party on Thursday night and we’d certainly love to meet as many of you as possible IRL, so head on over to https://tokenfest.adria.digital/ and get your tickets while you can. \n\n*Team Creary*",
    "json_metadata":
        "{\"tags\":[\"creary\",\"tokenfest\",\"conference\"],\"image\":[\"https://i.imgur.com/fOScDIW.png\"],\"links\":[\"https://tokenfest.adria.digital\",\"https://tokenfest.adria.digital/\"],\"app\":\"creary/0.1\",\"format\":\"markdown\"}",
    "last_update": "2018-03-07T23:22:54",
    "created": "2018-03-07T20:56:36",
    "active": "2018-03-13T01:40:21",
    "last_payout": "1970-01-01T00:00:00",
    "depth": 0,
    "children": 29,
    "net_rshares": "11453442114933",
    "abs_rshares": "11454054795840",
    "vote_rshares": "11454054795840",
    "children_abs_rshares": "13568695606090",
    "cashout_time": "2018-03-14T20:56:36",
    "max_cashout_time": "1969-12-31T23:59:59",
    "total_vote_weight": 3462435,
    "reward_weight": 10000,
    "total_payout_value": "0.000 CBD",
    "curator_payout_value": "0.000 CBD",
    "author_rewards": 0,
    "net_votes": 77,
    "root_comment": 37338948,
    "max_accepted_payout": "0.000 CBD",
    "percent_crea_dollars": 10000,
    "allow_replies": true,
    "allow_votes": true,
    "allow_curation_rewards": true,
    "beneficiaries": [],
    "url": "/creary/@crearyblog/join-team-creary-at-tokenfest",
    "root_title": "Join Team Creary at TokenFest!",
    "pending_payout_value": "46.436 CBD",
    "total_pending_payout_value": "0.000 CREA",
    "active_votes": [
        {
            "voter": "crearyblog",
            "weight": 0,
            "rshares": "1870813909383",
            "percent": 10000,
            "reputation": "128210130644387",
            "time": "2018-03-07T20:56:36"
        },
        {
            "voter": "kevinwong",
            "weight": 526653,
            "rshares": "2208942520687",
            "percent": 5000,
            "reputation": "374133832002581",
            "time": "2018-03-08T04:27:00"
        }
    ],
    "replies": [],
    "author_reputation": "128210130644387",
    "promoted": "0.000 CBD",
    "body_length": 754,
    "reblogged_by": []
}
'Selected: crearyblog/join-team-creary-at-tokenfest'

From this result you have access to everything associated to the post including additional metadata which is a JSON string (that must be decoded to use), active_votes info, post title, body, etc. details that can be used in further development of application with Python.

That’s it!

To Run the tutorial

  1. review dev requirements
  2. clone this repo
  3. cd tutorials/05_get_post_details
  4. pip install -r requirements.txt
  5. python index.py
  6. After a few moments, you should see output in terminal/command prompt screen.