<img src="https://i.hizliresim.com/Gygv9V.jpg">

Hello,

This is the third post of "steem-python for dummies" series. If you didn't read the first and second post, take your time and have a look.

1. [steem-python for dummies #1 - Introduction and Basic Operations](https://utopian.io/utopian-io/@emrebeyler/steem-python-for-dummies-1)
2. [steem-python for dummies #2 - Playing with account data](https://utopian.io/utopian-io/@emrebeyler/steem-python-for-dummies-2-playing-with-accounts)

In this post, we will study the **get_account_history** method of  and create a simple random upvote bot by using it.

#### Requirements of the bot

Bot,

- should listen transfers directed to it.
- should check the memo is valid 
- upvote the memo URL with a random vote (between 1 and 100) 

**Listening Operations**

One can listen transactions by listening new blocks in the each newly produced blocks. However, if you want to see just specific operations for specific accounts, then you have a shortcut. 

Usage:

```
from steem.account import Account

acc = Account('emrebeyler')
print(list(acc.get_account_history(-1, 1)))
```

See the raw [output](https://gist.githubusercontent.com/emre/6bffc3c08c99d5060a69f6b16e2051ea/raw/d0c1fbe81ebb4692f6010122f2193a8ffc777b9c/get_account_history_output.txt). It includes last two operations relating to my account in the chain.

get_account_history has a bunch of parameters for slicing the data, filtering the operations. It's well documented in the source code, copy/pasting from there.

| Parameter   |      Type      |  Help |
|----------|:-------------:|------:|
| index |  int | start index for get_account_history|
| limit |  int |  (Optional) skip items until this index|
| start | int |   (Optional) skip items until this index |
| stop | int |   (Optional) stop iteration early at this index|
| order | (1, -1) |   1 for chronological, -1 for reverse order|
| filter_by |  (str, list) |   filter out all but these operations|
| raw_output | (bool) | return history in raw format


So, for my case, What I am interested is "transfer" operations.

```
account_history = acc.get_account_history(-1, 100, filter_by=["transfer"])
```

This will return a list of transfer operations related to my account.

**Tip:** This will not return latest 100 transfers. Because filtering is done on the steem-python (client) side, so it will get last 100 operations and filter them by transfers.

#### Two steps of success

**First step:**

 Creating an Account instance with bot's posting key.

```
BOT_ACCOUNT = "BOT_ACCOUNT_USERNAME"
s = Steem(nodes=["https://rpc.buildteam.io"], keys=["PRIVATE_POSTING_KEYS"])
acc = Account(BOT_ACCOUNT, steemd_instance=s)
```

**Second step:**

 In an endless loop, check for all transfers and upvote the correct posts with a random vote weight.

```
while True:
    transfers = acc.get_account_history(-1, 250, filter_by=["transfer"])
    for transfer in transfers:
        if transfer["to"] != BOT_ACCOUNT:
            continue

        try:
            post = Post(transfer.get("memo"))
        except ValueError as e:
            if 'Invalid identifier' == e.args[0]:
                print("Invalid post link. Consider a refund. [%s]" %
                      transfer.get("memo"))
                continue

        # get a voting weight between 1 and 100
        vote_weight = float(random.randint(+1, +100))
        post.commit.vote(post.identifier, vote_weight, account=BOT_ACCOUNT)

        print("Sleeping for 3 seconds")
        time.sleep(3)

```

Voila! Bot constantly check for transfers sent to it, and if it sees a valid post, gives a random upvote. Also, reviews the memo is a valid post or not by using steem-python's built-in capabilities.

However, this bot is not production ready. If you want to continue developing it, here are my advises:

**Missing Features**

1. Refunds. 
2. Check for archived posts. (+7 days)
3. Check for duplicate transactions (Bot shouldn't vote same post again and again.)
4. Handle node timeout errors with a try/except blocks.

***

That's all for this post. Feel free to ask questions or request topics about steem-python for the incoming posts. 


<br /><hr/><em>Posted on <a href="https://utopian.io/utopian-io/@emrebeyler/steem-python-for-dummies-3-coding-an-upvote-bot">Utopian.io -  Rewarding Open Source Contributors</a></em><hr/>