Beem Tutorials #1 - Introduction to Beem and creating a post with it

Repository of Beem

https://github.com/holgern/beem

Tutorial Content

• You will learn how to get started with Beem.
• You will learn how to create a post via Beem.

Requirements

• Python 2.7.x or 3.4+
• Basic Python knowledge

Introduction

Beem is an alternative python library by @holger80 to interact with the STEEM blockchain.

After seeing it's constant development and getting very good feedbacks about the library, I have decided to switch to beem for my bots and scripts.

I will be learning Beem in the next couple of weeks and will write my experience on it as a tutorial series. Welcome to the first part of it.

Installation

Installing the library is already covered well in the official documentation. It supports both Python2.7+ and Python 3.4+ versions.

For the Osx, I have followed these steps to install:

$ mkvirtualenv -p python3.6 beemtutorials
$ pip install beem

Note: First line creates a virtual environment. It's the industry standard on python development at the moment. I highly suggest working
with virtual environments if you don't practise that way already.

Setting up the Steem instance

from beem import Steem
s = Steem()

print(s.get_blockchain_version())

You will see an output as 0.19.2.

This is the main class we use to interact with the blockchain. You can see the parameters and their definitions at source code/steem.py. However, you don't really need all of them. I will cover the important ones.

Setting a node

The first parameter is a list of nodes you want to connect. Let's run the same example with a different node:

from beem import Steem
s = Steem(
    node=["https://api.steemit.com",]
)

print(s.get_blockchain_version())

You will see the output has changed as 0.19.4 since api.steemit.com runs a newer version of steemd.

Setting keys

from beem import Steem
s = Steem(
    node=["https://api.steemit.com",],
    keys=["<private_key_1>", "<private_key_2>"]
)

Keys are private keys you have on steem accounts. If you want to create a post, you need posting private key entered here. However, storing keys raw in source codes may not be the best solution since you may push your
private keys to the repositories.

There are a couple of options to solve that issue:

• Using environment variables

import os

from beem import Steem
s = Steem(
    node=["https://api.steemit.com",],
    keys=[os.getenv("POSTING_KEY"), ]
)

This example gets the posting key from environment variables. You need to set that POSTING_KEY variable before executing the code.

POSTING_KEY=<posting_key_of_account> python script.py

• Using Beem's wallet

Beem has a wallet implementation to make account/wallet related options more practical.

The following code creates a wallet with unique-pass passphrase and adds a private key
into the wallet.

from beem import Steem
steem = Steem()
steem.wallet.create("unique-pass")
steem.wallet.unlock("unique-pass")
steem.wallet.addPrivateKey("<posting_wif>")

After doing that, whenever you need to broadcast something you can unlock the wallet by setting UNLOCK environment variable.

Note: If you already created a wallet and don't remember the password, you can wipe the old
wallet by

steem.wallet.wipe(True)

before creating a new wallet. Otherwise you will get an error states that there is already a wallet
exists.

You can also use the command line tool (beempy) ships with the package to perform
wallet related issues.

To create wallet:

$ beempy createwallet

To add private keys to the wallet:

$ beempy addkey <your_private_key>

Note: Beem stores wallet information on a SQLITE database. It's stored at ~/Library/Application\ Support/beem/beem.sqlite for my OSX setup. You can see where it's located from the steem.config object:

from beem import Steem
steem = Steem()
print(steem.config.data_dir)

Note: If you use Beem's wallet, you don't need to use the keys parameter
of Steem() since Beem will get keys from the unlocked wallet.

Creating a Post

You don't need any interface (Steemit, Busy, etc.) to create posts. Let's do it with Beem.

Note: Posts are actually are Comment objects in the steem blockchain. If a comment doesn't have any parent, that means it's a post.

I will explicitly set private posting key to keep things simple.

from beem import Steem
steem = Steem(
    keys=["<private_posting_wif>"]
)
steem.post(
    "My title for the post",
    "Beem is awesome! (post body)",
    author="beemtutorials",
    permlink="beemtutorials-test-post",
    app="myapp/0.0.1",
    tags="beem test test-post"
)

You can see the created post here. Let's see the possible parameters for the post:

The first two parameter are obviously post title and post body. However, post() functions can get lots of keyword arguments.

Parameter	Value
author	Author of the post. Not needed if you set a default account via beempy.
permlink	Permlink of the post. Should be unique together with author and permlink. If not set, beem will auto-generate it from title.
reply_identifier	Identifier (Ex: @author/permlink) for the parent post. Not needed if you create a new post. Required for comments.
json_metadata	Custom json metadata of the post. If you develop an app and need customized info, you can put it here.
comment_options	Some options for the post. You can specify: max_accepted_payout, percent_steem_dollars, allow_curation_rewards etc.
community	The community we're posting into. Example: Utopian was using "utopian" here. Overrides json_metadata.community.
app	The app used for creating the post. Busy, Steemit and other dapps puts their information here like "Busy/2.4.0"
tags	A list of tags for the post. Example: "steem steemit utopian beem"
beneficiaries	A list of beneficiaries for reward sharing.
self_vote	If you set this as True, author will upvote the created post right after the creation.

Beneficiaries is an interesting option here, we will discuss it in the upcoming tutorials in this series.

Curriculum

• Introduction to Beem and creating a post with it

Sample Codes

Samples

---

Thanks to @holger80 and @crokkon for the proof-reading and review.