<center>![steem-python.png](https://res.cloudinary.com/hpiynhbhq/image/upload/v1515886103/kmzfcpvtzuwhvqhgpyjp.png)</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 will explain how to upload images directly with an API and construct a post with the image.


---
#### Repository
https://github.com/steemit/steem-python

#### What will I learn

- Installing and configuring imgurpython
- Uploading an image to Imgur
- Constructing a post from a template
- Submitting a post to STEEM

#### Requirements

- Python3.6
- `steem-python`
- imgurpython

#### Difficulty
- basic
---

### Tutorial

#### Preface
The `STEEM Blockchain` allows for direct interaction without using websites like `steemit.com` or `busy.org`. Instead a `post` can be uploaded directly to the `Blockchain`. If one wants to include an image in this post a 3rd party host for this image is required. `Imgur` has an `API` which allows for easy uploading of images with `Python`.

#### Setup
Download the files from [Github](https://github.com/amosbastian/steempy-tutorials/tree/master/part_28). There 5 are files `post_submitter.py` which is the main file and takes two arguments `account` and `filename`, `imgur.py` which contains the code for uploading an image to Imgur, `EXIF.py` which extracts EXIF data from the image and `post.json` which is a JSON file containing information about the post and also 1 image file for testing.

Run scripts as following:
`> python post_submitter.py juliank post.json`

### Installing and configuring imgurpython

Installation is simple using pip:

```
pip3 install imgurpython
```
<br><center>
![Screenshot 2018-07-17 16.09.24.png](https://cdn.steemitimages.com/DQmaQwaQYgN3eUPTEABrsr2Jh1TUkrCCuwFYTauyGeZEfLC/Screenshot%202018-07-17%2016.09.24.png)</center>
<br>
However to use the `Imgur API` an account is required. Signing up up is free. Go to the following [link](https://api.imgur.com/oauth2/addclient) and create an account. After that a client has to be added for which you will receive a `client_id` and `client_secret`. Add these settings to the `imgur.py` file.
<br><center>
![Screenshot 2018-07-17 16.09.51.png](https://cdn.steemitimages.com/DQmRx2CH9z6pA2xS4G7KcDXtMHFe5Yj6V5T2QxzoLSMATLo/Screenshot%202018-07-17%2016.09.51.png)
</center>


#### Uploading an image to Imgur
The `Imgur API` is simple to use. After setting the account settings uploading an image is done by calling `upload_from_path()`, it requires the `path` of the `filename`. In this case `anon` is set to `True` so uploader is anonymous.

```
from imgurpython import ImgurClient

# account settings
client_id = ''
client_secret = ''

client = ImgurClient(client_id, client_secret)

```

Upon successful upload a `JSON dict` is returned containing all the information about the uploaded image.

```
{
	'id': 'kQPLkLs',
	'title': None,
	'description': None,
	'datetime': 1531837066,
	'type': 'image/jpeg',
	'animated': False,
	'width': 2222,
	'height': 1481,
	'size': 782184,
	'views': 0,
	'bandwidth': 0,
	'vote': None,
	'favorite': False,
	'nsfw': None,
	'section': None,
	'account_url': None,
	'account_id': 0,
	'is_ad': False,
	'in_most_viral': False,
	'has_sound': False,
	'tags': [],
	'ad_type': 0,
	'ad_url': '',
	'in_gallery': False,
	'deletehash': 'ppaO3Z1KasKq1lr',
	'name': '',
	'link': 'https://i.imgur.com/kQPLkLs.jpg'
}
```

From this dict the `link` is retrieved to be used in the `post`.

```
def upload_image(filename):
    # upload the image as anonymous
    image = client.upload_from_path(filename, anon=True)

    # retrieve only the image url from the retrieved json data
    # return the url
    url = image['link']
    return url
```


#### Constructing a post from a template

A `post` on `STEEM` requires more than a single image. The additional data required to submit a post is stored in `post.json`.


```
{
	"title": "Keeping Watch",
	"tags": "blog street photography zagreb croatia",
	"caption": "Or just enjoying the view that comes with the job?",
	"image": "1.jpg"
}
```

This data is taken from the `JSON` file and stored in `variables` to be submitted in a `post`.

```
def submit_post(self, account, filename):
    # Load post data
    post = json.load(open(filename))
    title = post['title']
    tags = post['tags']
    caption = post['caption']
    image = post['image']
```

The image is upload via the `Imgur API` returning a `url`.
```
# upload the image and retrieve the url
url = imgur.upload_image(image)
```

Optionally the image is processed for `EXIF` data which is put into a` table`, to read more about this follow this tutorial: [Extracting EXIF (Meta)Data From Images With Python](https://steemit.com/utopian-io/@steempytutorials/extracting-exif-meta-data-from-images-with-python)
```
# process the iamge for EXIF data to construct a table
table = exif.process_image(image)
```
With all the required data complete the `body` of the `post` be be constructed using a simple `template`. `"""` is used to create a `multi-line` string in `Python` and `textwrap.dedent()` is used to remove the tabs in front of each string. This allows for elegant formatting.


```
# Use template to construct a body for the post
body = textwrap.dedent(
    f"""
    <center>
    {caption}
    ---
    [![image]({url})]({url})
    ---

    {table}

    </center
    """)
```


#### Submitting a post to STEEM

Submitting a post to `STEEM` is done by calling the `post()` function on the `Steem object`. 8 out of the 11 arguments are optional, but can be customised depending on preferences.

```
def post(self,
         title,
         body,
         author,
         permlink=None,
         reply_identifier=None,
         json_metadata=None,
         comment_options=None,
         community=None,
         tags=None,
         beneficiaries=None,
         self_vote=False):
```

The `title` and `tags` were taken from `post.json`, the `body` was constructed and the `account` is set when calling `post_submitter.py`.

```
# Submit post to the Steem Blockchain
self.steem.post(title=title, body=body, author=account, tags=tags)
```

The function `post()` returns a `dict` with all the information about the `post` that was just submitted.

```
{
	'ref_block_num': 7964,
	'ref_block_prefix': 1056726494,
	'expiration': '2018-07-17T13:45:31',
	'operations': [
		['comment', {
			'parent_author': '',
			'parent_permlink': 'photography',
			'author': 'juliank',
			'permlink': 'keeping-watch',
			'title': 'Keeping Watch',
			'body': '\n<center>\nOr just enjoying the view that comes with the job?\n---\n[![image](https://i.imgur.com/mSIa5CN.jpg)])(https://i.imgur.com/mSIa5CN.jpg)\n---\n\n\n<table>\n<tr><td>Settings</td><td><b>ISO 100 85\nmm f/7/5 1/640 sec </b></td></tr>\n<tr><td>Camera</td><td><b>SONY ILCE-7M3</b></td></tr>\n<tr><td>Lens</td><td><b>FE 85mm F1.4 GM</b></td></tr>\n<tr><td>Date</td><td><b>2018:07:17 15:31:41</b></td></tr>\n</table>\n\n</center\n',
			'json_metadata': '{"tags": ["photography", "blog", "zagreb", "street", "croatia"]}'
		}]
	],
	'extensions': [],
	'signatures': ['2004881217455592399c83510cb4c55219f229ff681113972db4850e31634d700d74a02381aad27ac735cbaec0af2509336deed8d48a7f1844abb48518841f4f26']
}
```

Inside here information like the `permlink` which is required for `upvoting` the `post` can be found.

#### Running the script
Running the code will upload the image to imgur and construct a post that is submitted to the STEEM Blockchain

```
python post_submitter.py juliank post.json
```

![Screenshot 2018-07-17 16.37.35.png](https://cdn.steemitimages.com/DQmbawKcmoYPxRvByzkFuFzKexTjjXkF7ZK8Y8Fc1gKZJDJ/Screenshot%202018-07-17%2016.37.35.png)
<br>
The constructed post:

```
<center>
Or just enjoying the view that comes with the job?
---
[![image](https://i.imgur.com/mSIa5CN.jpg)](https://i.imgur.com/mSIa5CN.jpg)
---


<table>
<tr><td>Settings</td><td><b>ISO 100 85
mm f/7/5 1/640 sec </b></td></tr>
<tr><td>Camera</td><td><b>SONY ILCE-7M3</b></td></tr>
<tr><td>Lens</td><td><b>FE 85mm F1.4 GM</b></td></tr>
<tr><td>Date</td><td><b>2018:07:17 15:31:41</b></td></tr>
</table>

</center>
```

#### 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)
- [Extracting EXIF (Meta)Data From Images With Python](https://steemit.com/utopian-io/@steempytutorials/extracting-exif-meta-data-from-images-with-python)

---

The code for this tutorial can be found on [GitHub](https://github.com/amosbastian/steempy-tutorials/tree/master/part_28)!

This tutorial was written by @juliank.