How to add to the PYTHONPATH in Windows

Adding a directory to the PYTHONPATH environment variable in Windows allows Python to find additional modules and packages outside the default installation directories. To add a directory to the PYTHONPATH in Windows, follow these steps:

Open the "Start" menu and search for "Environment Variables" or "Edit the system environment variables". Click on the "System Properties" option that appears in the search results.
In the "System Properties" window, click on the "Environment Variables" button near the bottom right corner.
In the "Environment Variables" window, you'll see two sections: "User variables" and "System variables". You can add the new PYTHONPATH to either section, depending on whether you want the changes to apply only to the current user or to all users on the system.
Check if there's an existing PYTHONPATH variable in the chosen section:
- If it exists, select the PYTHONPATH variable, and click on the "Edit" button. In the "Edit environment variable" window, add a semicolon ; (if not already present) at the end of the existing value, followed by the full path of the directory you want to add (e.g., C:\my_python_modules). Click "OK" to save the changes.
- If it doesn't exist, click on the "New" button in the chosen section. In the "New environment variable" window, enter PYTHONPATH as the "Variable name" and the full path of the directory you want to add (e.g., C:\my_python_modules) as the "Variable value". Click "OK" to create the new variable.
Click "OK" to close the "Environment Variables" window and then click "OK" to close the "System Properties" window.
Restart any open Command Prompt or PowerShell windows for the changes to take effect. Now, Python should be able to locate and import modules from the added directory.

Please note that these steps are for adding a directory to the PYTHONPATH permanently. If you want to add a directory to the PYTHONPATH temporarily for a single session, you can run the following command in Command Prompt or PowerShell:

$env:PYTHONPATH = "C:\my_python_modules;$env:PYTHONPATH"

Replace C:\my_python_modules with the path of the directory you want to add.

Add directory to PYTHONPATH Windows:
- Description: PYTHONPATH is an environment variable that specifies directories where Python looks for modules to import.
- Example: Open a command prompt and use the following command to add a directory to PYTHONPATH temporarily:
```
set PYTHONPATH=%PYTHONPATH%;C:\path\to\your\directory
```
Setting PYTHONPATH environment variable in Windows:
- Description: Set the PYTHONPATH environment variable to include directories where Python should search for modules.
- Example: Permanently set PYTHONPATH in PowerShell:
```
[System.Environment]::SetEnvironmentVariable("PYTHONPATH", "C:\path\to\your\directory", [System.EnvironmentVariableTarget]::User)
```
How to modify PYTHONPATH in Windows:
- Description: Modify PYTHONPATH by adding or removing directories to control Python module search paths.
- Example: To append a directory to PYTHONPATH in a Python script:
```
import sys
sys.path.append("C:\\path\\to\\your\\directory")
```
Adding a folder to Python path in Windows 10:
- Description: In Windows 10, you can add a folder to the Python path using command prompt or PowerShell.
- Example: Use the command prompt to add a folder to PYTHONPATH:
```
setx PYTHONPATH "%PYTHONPATH%;C:\path\to\your\directory"
```
Windows command prompt PYTHONPATH configuration:
- Description: Configure PYTHONPATH in the Windows command prompt to include directories for Python module search.
- Example: Use set command in command prompt:
```
set PYTHONPATH=%PYTHONPATH%;C:\path\to\your\directory
```
Modifying user-specific PYTHONPATH in Windows:
- Description: Modify user-specific PYTHONPATH in Windows to customize Python module search paths for a specific user.
- Example: Use PowerShell to set user-specific PYTHONPATH:
```
[System.Environment]::SetEnvironmentVariable("PYTHONPATH", "C:\path\to\your\directory", [System.EnvironmentVariableTarget]::User)
```