# 🐍 Writing Python-Based Methods

To implement a method in Python, you typically use the standard `python` Docker image via the `ccpimage` input.

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## 🐳 Choosing the Python Runtime

Use `ccpimage` to select a Docker image like `python:3.9.19`:

![Python Image](/_static/imgs/input_ccpimage_python.png)

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## 📁 Linking to Your Source Code

You can use an input field like `repository` to let users specify the location of your code:

![Repository Input](/_static/imgs/input_repository.png)

This repository will be cloned at runtime by the **deploy script**.

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## 🚀 Example Scripts

### 🔧 Deploy Script

```bash
git clone {{repository}} repo
pip install -r repo/requirements.txt
```

### ▶️ Execute Script

```bash
cd repo
python myapp.py
```

These scripts go in your `method.json`:

```json
"additionalParameters": {
  "parameters": [
    {
      "name": "deploy-script",
      "value": [
        "git clone {{repository}} repo",
        "pip install -r repo/requirements.txt"
      ]
    },
    {
      "name": "execute-script",
      "value": [
        "cd repo",
        "python myapp.py"
      ]
    }
  ]
}
```

---

## 🧪 Tip: Use `argparse` to expose parameters

Your Python script should expose configurable parameters:

```python
import argparse

parser = argparse.ArgumentParser()
parser.add_argument("--input", required=True)
parser.add_argument("--output", required=True)
parser.add_argument("--threshold", type=float, default=0.5)
args = parser.parse_args()
```

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## 📄 Example Method

See the full [WordCloud Example](/_static/methods_examples/WordCloud-1.0.0.json)

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## 🔗 Related Pages

- 👨‍💻 [Building simple methods](/01_quickstart/05_building_simple_method)

- 🛠 [Script syntax and placeholders](./06_scripts_and_placeholders)

- 🐧 [Docker image field (`ccpimage`)](./02_defining_ccpimage)

- 🔣 [Structure of method.json](./07_method_json)