Hive Developer Portal
PY: Get Posts
Tutorial pulls a list of the posts from the blockchain with selected filter and tag then displays output.
Full, runnable src of Get Posts can be downloaded as part of: tutorials/python.
This tutorial will explain and show you how to access the Steem blockchain using the steem-python library to fetch list of posts filtered by a filter and tag
Intro
In Steem there are built-in filters trending, hot, created, active, promoted etc. which helps us to get list of posts. get_discussions_by_trending(query), get_discussions_by_hot(query), get_discussions_by_created(query), etc. functions are built-in in official library steem-python that we are going to use throughout all Python tutorials.
Steps
- App setup - Library install and import
- Filters list - List of filters to select from
- Query details - Form a query
- Print output - Print results in output
1. App setup
In this tutorial we use 3 packages, pick - helps us to select filter interactively. steem - steem-python library, interaction with Blockchain. pprint - print results in better format.
First we import all three library and initialize Steem class
import pprint
from pick import pick
# initialize Steem class
from steem import Steem
s = Steem()
2. Filters list
Next we will make list of filters and setup pick properly.
title = 'Please choose filter: '
#filters list
options = ['trending', 'hot', 'active', 'created', 'promoted']
# get index and selected filter name
option, index = pick(options, title)
This will show us list of filters to select in terminal/command prompt. And after selection we will get index and filter name to index and option variables.
3. Query details
Next we will form a query. In Steem,
- You can add a tag to filter the posts that you receive from the server
- You can also limit the amount of results you would like to receive from the query
query = {
"limit":2, #number of posts
"tag":"" #tag of posts
}
#post list for selected query
posts = {0: s.get_discussions_by_trending(query),
1: s.get_discussions_by_hot(query),
2: s.get_discussions_by_active(query),
3: s.get_discussions_by_created(query),
4: s.get_discussions_by_promoted(query)
}
Above code shows example of query and simple list of function that will fetch post list with user selected filter.
4. Print output
Next, we will print result, post list and selected filter name.
# print post list for selected filter
pprint.pprint(posts[index])
pprint.pprint("Selected: "+option)
The example of result returned from the service is a JSON object with the following properties:
[
{
"id": 37338948,
"author": "steemitblog",
"permlink": "join-team-steemit-at-tokenfest",
"category": "steemit",
"parent_author": "",
"parent_permlink": "steemit",
"title": "Join Team Steemit at TokenFest!",
"body":
"<a href=\"https://tokenfest.adria.digital\"><img src=\"https://i.imgur.com/fOScDIW.png\"/></a>\n\nHello Steemians! If you’d like to meet Team Steemit 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\nSteemit CEO, Ned Scott, will be participating in a fireside chat alongside Steemit’s CTO, Harry Schmidt, as well as the creator of Utopian.io, Diego Pucci. Steemit 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 Steemit*",
"json_metadata":
"{\"tags\":[\"steemit\",\"tokenfest\",\"conference\"],\"image\":[\"https://i.imgur.com/fOScDIW.png\"],\"links\":[\"https://tokenfest.adria.digital\",\"https://tokenfest.adria.digital/\"],\"app\":\"steemit/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 SBD",
"curator_payout_value": "0.000 SBD",
"author_rewards": 0,
"net_votes": 77,
"root_comment": 37338948,
"max_accepted_payout": "0.000 SBD",
"percent_steem_dollars": 10000,
"allow_replies": true,
"allow_votes": true,
"allow_curation_rewards": true,
"beneficiaries": [],
"url": "/steemit/@steemitblog/join-team-steemit-at-tokenfest",
"root_title": "Join Team Steemit at TokenFest!",
"pending_payout_value": "46.436 SBD",
"total_pending_payout_value": "0.000 STEEM",
"active_votes": [
{
"voter": "steemitblog",
"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 SBD",
"body_length": 754,
"reblogged_by": []
},
{
}
]
'Selected: hot'
From this result you have access to everything associated to the posts 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
- review dev requirements
git clone https://gitlab.syncad.com/hive/devportal.gitcd devportal/tutorials/python/04_get_postspip install -r requirements.txtpython index.py- After a few moments, you should see output in terminal/command prompt screen.