Execute Your Python Scripts With a Shebang (Overview)

Emmanuel Nwokocha
Execute Your Python Scripts With a Shebang Emmanuel Nwokocha 01:59
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In shell scripts, the shebang line (#!) specifies the path to the interpreter that should execute the file. You can place it at the top of your Python file to tell the shell how to run your script, allowing you to execute the script directly without typing python before the script name. The shebang is essential for Unix-like systems but ignored on Windows unless using specific compatibility layers.

By the end of this video course, you’ll understand that:

  • A shebang specifies the path to the Python interpreter in scripts, allowing direct execution.
  • You should include a shebang when a script needs direct execution, but not in import-only modules.
  • Best practices for shebangs include using /usr/bin/env for portability and ensuring the script is executable.
  • Shebangs have limitations, such as being ignored on Windows without compatibility layers like WSL.

Prerequisite resources linked in this lesson:

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00:00 Welcome to this course, Executing Python Scripts With a Shebang. I’m Emmanuel, and I’m happy to be your guide through this course. If you are fairly new to Python or even experienced, and have had the privilege of reading some Python code written by other developers, you might have spotted the shebang at some point.

00:17 The syntax for a Python shebang looks something like this written either in a form hash symbol and exclamation mark /usr/bin/ python3 or hash symbol exclamation mark / usr/bin/env python3.

00:37 If you’ve seen any of these before and wondered what it is and why it’s included in certain scripts, this course will help with that.

00:45 By the end of this course, you’ll understand how the shebang is used to specify the Python interpreter path for executing scripts, what types of scripts benefit the most from using a shebang, how to define portable shebangs, environment-specific limitations of the shebang and its alternatives, and best practices when using the shebang.

01:06 So the next time you see the shebang in a script, you’ll understand its purpose, and not just that, you start to use it well yourself.

01:14 For this course, it will be helpful to already have basic familiarity with the command line, and how to run Python scripts from it. If you need a guide, there are some courses here on Real Python that can help with that.

01:25 One is this tutorial: Build Command-Line Interfaces With Python’s argparse. In this tutorial, you’ll learn about the argparse module and how it helps to build command-line interfaces.

01:36 Another is a tutorial, How to Run Your Python Scripts and Code. In this tutorial, you’ll learn various methods for executing Python scripts in different environments and platforms.

01:47 Links to these are provided in the slides in the additional resources section, along with sample code files used in this course.

01:55 With that sorted, you can get started in the next lesson.

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