# Scenerio

You are trying to pack up your code and packages for lambda, you face this error, what might have happened.

{
  "errorMessage": "Unable to import module 'lambda_function': No module named 'lambda_function'",
  "errorType": "Runtime.ImportModuleError",
  "requestId": "",
  "stackTrace": []
}

> [!Tip] To read more about packaging lambda:
> 補充教材 - [**利用 AI 工具把 Python 程式碼轉換成 Lambda 可以運行的格式，然後打包上傳 & Lambda 常見應用及可以解決客戶哪些痛點**](https://www.notion.so/AI-Python-Lambda-Lambda-14e6bfee6817804d906dfae67e3318d4?pvs=21)

# Breakdown

## Let’s take a look at the zip file

### Situation 1 : Select all the files and compress

**function.zip**
├── __pycache__
├── _mysql_connector.cpython-311-darwin.so
├── beautifulsoup4-4.12.2.dist-info
...
├── urllib3
├── urllib3-2.0.7.dist-info
└── **lambda_function.py**


### Situation 2 : Select the folder and compress

**function.zip**
└── **function**
		├── __pycache__
		├── _mysql_connector.cpython-311-darwin.so
		├── beautifulsoup4-4.12.2.dist-info
		...
		├── urllib3
		├── urllib3-2.0.7.dist-info
		└── **lambda_function.py**


## So what’s the difference if you upload this to lambda.

### Situation 1 : Select all the files and compress

> [!Note]
> Your **lambda_function.py** and packages are in the parent folder which is named after the lambda.


### Situation 2 : Select the folder and compress

> [!Note]
> Your **lambda_function.py** and packages are in the function folder you have compressed.


## So what happens behind the error ?

The reason is that the settings of **Handler** is wrong.


**`lambda_function`**

- **檔案名稱**：`lambda_function.py` 是 Lambda 執行程式碼的檔案名稱，告訴 Lambda **程式碼在哪裡**。
- 例如，如果你的檔案是 `lambda_function.py`，Lambda 就會從這個檔案中尋找入口函式。

**`lambda_handler`**

- **入口函式名稱**：`lambda_handler` 是檔案中用來處理事件的函式名稱，Lambda 會從這個函式開始執行程式邏輯。
- 這是 AWS 預設的函式名稱，但你可以在 Lambda 設定中自訂。

> [!Important]
> **`lambda_function.lambda_handler`** is for situation 1 and **`function.lambda_function.lambda_handler`** is for situation 2

</aside>

### Add a folder name (`function`) in front of the handler.


## Let’s test Situation 2 again !

### This time we got this error

{
  "errorMessage": "Unable to import module 'function.lambda_function': No module named 'requests'",
  "errorType": "Runtime.ImportModuleError",
  "requestId": "",
  "stackTrace": []
}

> [!Note]
> ### We can’t locate where all my imported packages is !
> Situation 1 is the normal case and you won't get this error !

To fix this, simply add `sys.path` to your **lambda_function.py**

import sys
import os

sys.path.append(os.path.dirname(os.path.abspath(__file__)))

- **What it does:** Adds the **current directory** (where the lambda_function.py file resides) to the sys.path.
- **When it works:** This works if the requests package is already located in the **same directory** as lambda_function.py or is structured in a way that Python can directly find it there.
- **Why it works:** When Python tries to resolve an import statement, **it checks each directory in sys.path in order.** By adding the current directory, you’re ensuring that Python can find any modules or packages in the same folder as lambda_function.py.

> [!Note]
> ### Everything works fine after that !!!