How can Python script be executable on Unix?

There are several methods to execute Python scripts on Unix systems:

1. Directly using the Python interpreter

First, ensure that Python is installed on your system. Enter the following command in the terminal to check if Python is installed and its version:

bash
python --version
# Or for Python 3
python3 --version

If Python is installed, run the script with the following command:

bash
python script.py
# Or for Python 3
python3 script.py

2. Making the script directly executable

First, add a shebang line at the very top of the script. This line specifies which interpreter should be used to execute the script. For Python scripts, it typically appears as:

python
#!/usr/bin/env python3

Next, modify the file permissions to make it executable. Use the following command:

bash
chmod +x script.py

Now, you can run the script directly using:

bash
./script.py

3. Using an IDE or text editor

Many integrated development environments (IDEs) and text editors, such as PyCharm and VSCode, support running Python scripts directly. This usually involves opening the script file and clicking a "Run" button.

Example demonstration

Suppose you have a file hello.py with the following content:

python
#!/usr/bin/env python3
print("Hello, World!")

To run it on a Unix system, follow the steps outlined in point 2 above:

1. Modify file permissions:

   bash
   chmod +x hello.py

2. Execute the file:

   bash
   ./hello.py

The output will be:

shell
Hello, World!

These are several common methods to execute Python scripts on Unix systems, and I hope this helps you understand how to run Python code on these systems.