### Install TestRail API Python Wrapper

Source: https://github.com/tolstislon/testrail-api/blob/master/README.md

Instructions for installing the `testrail-api` Python package using pip, the standard Python package installer.

```bash
pip install testrail-api
```

--------------------------------

### Install Development Dependencies for TestRail API

Source: https://github.com/tolstislon/testrail-api/blob/master/README.md

Commands to install development dependencies using `pipenv` and activate the project's virtual environment, preparing the development setup.

```bash
pipenv install --dev
pipenv shell
```

--------------------------------

### Basic TestRail API Usage Example in Python

Source: https://github.com/tolstislon/testrail-api/blob/master/README.md

Demonstrates how to initialize the TestRail API client and perform common operations such as adding a milestone, creating a test run, adding a test result, attaching a file, and closing a run and milestone.

```python
from datetime import datetime

from testrail_api import TestRailAPI

api = TestRailAPI("https://example.testrail.com/", "example@mail.com", "password")

# if use environment variables
# api = TestRailAPI()


new_milestone = api.milestones.add_milestone(
    project_id=1,
    name="New milestone",
    start_on=datetime.now()
)

my_test_run = api.runs.add_run(
    project_id=1,
    suite_id=2,
    name="My test run",
    include_all=True,
    milestone_id=new_milestone["id"]
)

result = api.results.add_result_for_case(
    run_id=my_test_run["id"],
    case_id=5,
    status_id=1,
    comment="Pass",
    version="1"
)
attach = "screenshots/attach.jpg"
api.attachments.add_attachment_to_result(result["id"], attach)

api.runs.close_run(my_test_run["id"])
api.milestones.update_milestone(new_milestone["id"], is_completed=True)
```

--------------------------------

### Configure TestRail API with Environment Variables

Source: https://github.com/tolstislon/testrail-api/blob/master/README.md

Example of environment variables that can be set to configure the TestRail API client, including the TestRail instance URL, user email, and password.

```dotenv
TESTRAIL_URL=https://example.testrail.com/
TESTRAIL_EMAIL=example@mail.com
TESTRAIL_PASSWORD=password
```

--------------------------------

### Run Flake8 Linter for TestRail API

Source: https://github.com/tolstislon/testrail-api/blob/master/README.md

Command to run `flake8`, a Python linter, to check for style guide violations and potential errors in the codebase.

```bash
pipenv run flake8
```

--------------------------------

### Run Tests for TestRail API Project

Source: https://github.com/tolstislon/testrail-api/blob/master/README.md

Command to execute the project's test suite, verifying the functionality and correctness of the `testrail-api` wrapper.

```bash
pipenv run tests
```

--------------------------------

### Clone TestRail API Repository for Contribution

Source: https://github.com/tolstislon/testrail-api/blob/master/README.md

Commands to clone the `testrail-api` GitHub repository and navigate into its directory, serving as the first step for local development and contributions.

```bash
git clone https://github.com/tolstislon/testrail-api.git
cd testrail-api
```

--------------------------------

### Run Black Formatter for TestRail API

Source: https://github.com/tolstislon/testrail-api/blob/master/README.md

Command to execute the `black` code formatter, ensuring consistent code style across the project.

```bash
pipenv run black
```

--------------------------------

### Implement Custom Response Handler for TestRail API

Source: https://github.com/tolstislon/testrail-api/blob/master/README.md

Illustrates how to define and integrate a custom response handler function with the TestRail API client. This allows for custom processing of API responses, such as error handling or specific data parsing.

```python
from datetime import datetime
import simplejson

from testrail_api import TestRailAPI


def my_handler(response):
    if response.ok:
        return simplejson.loads(response.text)
    return 'Error'


api = TestRailAPI("https://example.testrail.com/", "example@mail.com", "password", response_handler=my_handler)
new_milestone = api.milestones.add_milestone(
    project_id=1,
    name="New milestone",
    start_on=datetime.now()
)
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.