<center></center>
This tutorial is part of a series where different aspects of programming with `steem-python` are explained. Links to the other tutorials can be found in the curriculum section below. This part is a direct continuation of [Part 23: Retrieve And Process Full Blocks From The Steem Blockchain](https://steemit.com/utopian-io/@steempytutorials/part-23-retrieve-and-process-full-blocks-from-the-steem-blockchain) and will go into more detail following `operation types`: `transfer`, `transfer_to_vesting`, `withdraw_vesting` and `convert`.
---
#### Repository
https://github.com/steemit/steem-python
#### What will I learn
- How to access data in a operation
- What is a transfer?
- What is a transfer_to_vesting
- What is a withdraw_vesting
- What is a convert?
#### Requirements
- Python3.6
- `steem-python`
#### Difficulty
- basic
---
### Tutorial
#### Setup
Download the files from [Github](https://github.com/amosbastian/steempy-tutorials/tree/master/part_24). There 2 are files `get_blocks.py` which contains the code. The main file takes 3 arguments from the command line which sets the `starting_block`, `block_count` and what `operation` to filter for.
Run scripts as following:
`> python get_block.py 22224731 10 transfer`
#### How to access data in a operation
The previous tutorial went into great detail how to extract `operations` from `blocks`. There are 19 different `operations` in total and each has a different structure. However, the data for the `operation` is always stored in the same spot.
```
{
'ref_block_num': 8004,
'ref_block_prefix': 1744181707,
'expiration': '2018-05-07T15:29:54',
'operations': [
['vote', {
'voter': 'acehjaya',
'author': 'zunaofficial79',
'permlink': 'kabut-pagi',
'weight': 10000
}]
],
'extensions': [],
'signatures': ['1f205086670c27365738697f0bc7cfde8b6e976608dc12b0d391b2b85ad7870a002313be4b09a358c30010be2a09bebacead866ba180afc348ce40c70566f4ed88']
}
```
<br>
Under `operations` is an array, the first index is the `operation type` and the second index is a `json table` with the `operation data`.
```
if transaction['operations'][0][0] == self.tag:
self.process_operation(transaction['operations']
[0][1],
self.tag)
```
Filter for the required operation type and process the `json data`. For this example tutorial a different `class` is made for each `operation type` which stores the data in respective `variables` and has a `print function`. These classes can be found in the `operations.py` file.
#### What is a transfer?
Every `transfer` of either `Steem` or `SBD` between two different user accounts is a `transfer` operation. This operation has 4 variables. `from` is the account that sends the funds, `to` the receiving account, `amount` the valuation and which currency, and optionally `memo`. In which messages can be added.
```
{
'from': 'yusril-steem',
'to': 'postpromoter',
'amount': '5.000 SBD',
'memo': 'https://steemit.com/life/@yusril-steem/our-challenges-and-trials-in-life'
}
```
<br>
By using a `class` to process the `operation` all the `variables` can be neatly kept and additional `functions` can be added as well. Like the `print_operation()` which allows for easy printing to the terminal. A separate `class` is made for each of the `operations` discussed in this tutorial.
```
class Transfer():
def __init__(self, operation, block, timestamp):
self.account = operation['from']
self.to = operation['to']
self.amount = operation['amount']
self.memo = operation['memo']
self.block = block
self.timestamp = timestamp
def print_operation(self):
print('\nBlock:', self.block, self.timestamp)
print('Operation: transfer')
print('From:', self.account)
print('To:', self.to)
print('Amount:', self.amount)
print('Memo:', self.memo)
print('')
```
<br>
Additional data that normally falls outside the scope of the `operation` can also be stored in the `class`. Like the `block` in which the `operation` took place and the timestamp of the `operation`.
#### What is a transfer_to_vesting
A `power up` of `Steem` by a user is known as a `transfer_to_vesting` and contains 3 `variables`. `from` the user account itself, `to` the receiving account and `amount` the amount being powered up. This `operation` locks up the `Steem` for 13 weeks.
```
{
'from': 'flxsupport',
'to': 'ltcil',
'amount': '0.719 STEEM'
}
```
<br>
#### What is a withdraw_vesting
Opposite to a `transfer_to_vesting` is a `withdraw_vesting`. When a user initiates a `power down` the amount of `steem power` will be powered down in 13 weekly increments. `Vested steem power` is displayed in `VESTS` and has to be converted to `Steem` based on the current conversion rate. This is outside the scope of this tutorial but can be found [here](https://steemit.com/utopian-io/@steempytutorials/part-22-calculate-account-value-based-on-current-market-prices-via-api). This `operation` holds 2 different `variables`. `account` the user account and `vesting_shares` the amount of `VESTS` to be converted to `Steem` at the time of the operation.
```
{
'account': 'bazimir',
'vesting_shares': '44671.906021 VESTS'
}
```
<br>
#### What is a convert?
It is possible to convert `SBD` to `Steem` on the `internal market`. This `operation` assumes that the value of `SBD` is at $1.0, which may not be true. Always check the `external markets` before doing such an `operation`. After 3 days the `operation` matures and the user will receive the `Steem`. This `operation` holds 3 different `variables`: `amount` the amount of `SBD` to be converted, `owner` the account initiating the conversion and `requestid` the id for the system to perform the conversion after 3 days.
```
{
'amount': '5000.0 SBD',
'owner': 'steemit',
'requestid': 1467592156
}
```
<br>
#### Running the script
Running the script will print the `operations`, for which the filter has been set, to the terminal starting from the `starting_block` for `block_count` amount of `blocks`. A `class` object is made for the `operation` and the build in `print_operation()` function is called. The data of the `operation` is printed to the terminal with the additional information of the `block` in which the `operation` is contained and the `timestamp` of the `operation`.
```
python get_blocks.py 22224731 10 transfer
Booted
Connected to: https://rpc.buildteam.io
Block: 22224731
Block: 22224731 2018-05-07T15:20:03
Operation: transfer
From: hottopic
To: jgullinese
Amount: 0.001 SBD
Memo: Hello Friend, Your post will be more popular and you will find new friends.We provide "Resteem upvote and promo" service.Resteem to 18.000+ Follower,Min 45+ Upvote.Send 1 SBD or 1 STEEM to @hottopic (URL as memo) Service Active
Block: 22224731 2018-05-07T15:20:03
Operation: transfer
From: minnowbooster
To: msena
Amount: 0.001 SBD
Memo: You got an upgoat that will be done by bycz,greece-lover,hemanthoj,percygeorge,bigdave2250,mexresorts,wanxlol,nickmorphew,thauerbyi,blackbergeron,aziz96,lovlu,utube,lowestdefinition. We detected an open value of 0.0$, worth 0.001 SBD in send and refunding that! Request-Id: 1176288
...
...
...
```
#### Curriculum
##### Set up:
- [Part 0: How To Install Steem-python, The Official Steem Library For Python](https://steemit.com/utopian-io/@amosbastian/how-to-install-steem-python-the-official-steem-library-for-python)
- [Part 1: How To Configure The Steempy CLI Wallet And Upvote An Article With Steem-Python](https://steemit.com/utopian-io/@steempytutorials/part-1-how-to-configure-the-steempy-cli-wallet-and-upvote-an-article-with-steem-python)
##### Filtering
- [Part 2: How To Stream And Filter The Blockchain Using Steem-Python](https://steemit.com/utopian-io/@steempytutorials/part-2-how-to-stream-and-filter-the-blockchain-using-steem-python)
- [Part 6: How To Automatically Reply To Mentions Using Steem-Python](https://steemit.com/utopian-io/@steempytutorials/part-6-how-to-automatically-reply-to-mentions-using-steem-python)
- [Part 23: Part 23: Retrieve And Process Full Blocks From The Steem Blockchain](https://steemit.com/utopian-io/@steempytutorials/part-23-retrieve-and-process-full-blocks-from-the-steem-blockchain)
##### Voting
- [Part 3: Creating A Dynamic Autovoter That Runs 24/7](https://steemit.com/utopian-io/@steempytutorials/part-3-creating-a-dynamic-upvote-bot-that-runs-24-7-first-weekly-challenge-3-steem-prize-pool)
- [Part 4: How To Follow A Voting Trail Using Steem-Python](https://steemit.com/utopian-io/@steempytutorials/part-4-how-to-follow-a-voting-trail-using-steem-python)
- [Part 8: How To Create Your Own Upvote Bot Using Steem-Python](https://steemit.com/utopian-io/@steempytutorials/part-8-how-to-create-your-own-upvote-bot-using-steem-python)
##### Posting
- [Part 5: Post An Article Directly To The Steem Blockchain And Automatically Buy Upvotes From Upvote Bots](https://steemit.com/utopian-io/@steempytutorials/part-5-post-an-article-directly-to-the-steem-blockchain-and-automatically-buy-upvotes-from-upvote-bots)
- [Part 7: How To Schedule Posts And Manually Upvote Posts For A Variable Voting Weight With Steem-Python](https://steemit.com/utopian-io/@steempytutorials/part-7-how-to-schedule-posts-and-manually-upvote-posts-for-a-variable-voting-weight-with-steem-python)
###### Constructing
- [Part 10: Use Urls To Retrieve Post Data And Construct A Dynamic Post With Steem-Python](https://steemit.com/utopian-io/@steempytutorials/part-10-use-urls-to-retrieve-post-data-and-construct-a-dynamic-post-with-steem-python)
##### Rewards
- [Part 9: How To Calculate A Post's Total Rewards Using Steem-Python](https://steemit.com/utopian-io/@steempytutorials/how-to-calculate-a-post-s-total-rewards-using-steem-python)
- [Part 12: How To Estimate Curation Rewards Using Steem-Python](https://steemit.com/utopian-io/@steempytutorials/part-12-how-to-estimate-curation-rewards)
- [Part 14: How To Estimate All Rewards In Last N Days Using Steem-Python](https://steemit.com/utopian-io/@steempytutorials/how-to-estimate-all-rewards-in-last-n-days-using-steem-python)
##### Transfers
- [Part 11: How To Build A List Of Transfers And Broadcast These In One Transaction With Steem-Python](https://steemit.com/utopian-io/@steempytutorials/part-11-how-to-build-a-list-of-transfers-and-broadcast-these-in-one-transaction-with-steem-python)
- [Part 13: Upvote Posts In Batches Based On Current Voting Power With Steem-Python](https://steemit.com/utopian-io/@steempytutorials/part-13-upvote-posts-in-batches-based-on-current-voting-power-with-steem-python)
##### Account Analysis
- [Part 15: How To Check If An Account Is Following Back And Retrieve Mutual Followers/Following Between Two Accounts](https://steemit.com/utopian-io/@steempytutorials/part-15-how-to-check-if-an-account-is-following-back-and-retrieve-mutual-followers-following-between-two-accounts)
- [Part 16: How To Analyse A User's Vote History In A Specific Time Period Using Steem-Python](https://steemit.com/utopian-io/@steempytutorials/part-16-how-to-analyse-a-user-s-vote-history-in-a-specific-time-period-using-steem-python)
- [Part 18: How To Analyse An Account's Resteemers Using Steem-Python](https://steemit.com/utopian-io/@steempytutorials/part-18-how-to-analyse-an-account-s-resteemers)
---
The code for this tutorial can be found on [GitHub](https://github.com/amosbastian/steempy-tutorials/tree/master/part_24)!
This tutorial was written by @juliank.
hiveblocks