Executing python in linux

Run Python Scripts in Linux Command Line

This quick tip shows how to run Python programs from the Linux command line.

If you want to do something, it is pretty much guaranteed that there is a Python script for it. So, when you have a Python script, how do you run it?

The simplest way is to use the python or python3 command in the following manner:

Some distributions have used python2 as python and have an explicit command python3 for python3. So if you want Python 3 to be guaranteed, use python3 .

Method 1: Run it using python

The easiest method to run a Python script on any Linux distribution is by invoking the python command and provide it with the name of your Python script.

This will ensure that if the file’s contents are valid, it will be executed without any problems.

Method 2: Make Python script executable

You may have encountered executing bash scripts simply by typing out their relative/absolute path in the terminal. i.e. you never had to do a bash .sh like you do with Python scripts by typing python .py

In order to achieve this, a few things should be done first.

If you might have noticed, the bash scripts that you can execute by simply typing out their relative/absolute path, they are «executable» files.

To make your Python script executable, run the following command in your terminal:

This should be it. Right? I have a file hello.py , let’s try running it.

$ cat hello.py print("Hello Linux Handbook!") $ chmod +x hello.py $ ./hello.py ./hello.py: 1: Syntax error: word unexpected (expecting ")")

Uh oh. What? Syntax error? But it is a valid Python program/script.

The reason why we got this error is because by making hello.py an executable file, all we did was tell the shell that «You can execute it», but not what interpreter/program to use when it is being executed.

My shell (bash) thought that it was a bash script. And hence, we got this error.

The solution to overcome this is pretty simple. Add the following line to the first line of your Python script.

The #! syntax is used mostly in scripts (where you need an interpreter). Now, the /usr/bin/env part means that we are calling env to find the python command from $PATH and execute it for us.

This essentially starts Python for us, instead of the user needing to invoke it manually every time. And, if you don’t automate these things, are you even scripting?

Another reason to use env in shebang is to make it portable. Some systems have the Python executable interpreter stored as /usr/local/bin/python , while some might have /usr/bin/python .

Now, let’s try executing hello.py once again, but with the necessary changes made to it.

$ sed -i '1 i\#!/usr/bin/env python\n' hello.py $ cat hello.py #!/usr/bin/env python print("Hello Linux Handbook!") $ ./hello.py Hello Linux Handbook!

Oh hey! It runs flawlessly now.

Now that you know how to run Python programs from the terminal, how about learning to use Linux commands from Python scripts?

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How to Run Python Scripts in Linux and Execute Linux Commands in Python

Learn how to run Python scripts in Linux and execute Linux commands in Python with this comprehensive guide. Follow the best practices and automate Python scripts in Linux.

• Creating and Running Python Scripts in the Command Line
• Executing Linux Commands in Python
• How to run Python scripts in Linux
• Running Python Scripts Automatically in Linux
• Running Python Scripts in Windows
• Best Practices for Python Programming
• Additional code samples that can be helpful for running Python scripts in Linux
• Conclusion
• How do I run a .py code?
• How do I run a Python script in Ubuntu?
• How do I run a Python script automatically in Linux?
• How do I run a Python script in Linux without typing?

Running Python scripts in Linux and executing Linux commands in Python is a valuable skill for developers and system administrators. By following some simple steps, users can run Python scripts from the terminal or command line, execute Linux commands in their Python code, and automate Python scripts in Linux. In this article, we will provide a comprehensive guide on how to run Python scripts in Linux and execute linux commands in python, including best practices, tips, and helpful resources.

Creating and Running Python Scripts in the Command Line

To run a Python script in Linux, open the terminal and navigate to the directory where the script is located. Here are the steps you need to follow:

1. Create a file with the .py extension and add the code.
2. Make sure the first line of your file has “#!/usr/bin/env python” to let the script call the interpreter.
3. Type “python” followed by the file name to run the script.
4. Use the exit() or quit() command to quit the Python program.

Here is a sample Python code that prints “Hello, world!” to the console:

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

Save this code to a file named “hello.py” and run it using the following command:

This will output “Hello, world!” to the console.

Executing Linux Commands in Python

To execute linux commands in Python, use the os.system() function. This function allows users to execute shell commands in python, including Linux commands. Here is an example of how to use os.system() to execute the Linux command “ls -l»:

This will output the list of files in the current directory to the console.

How to run Python scripts in Linux

In this video I show how one can run python scripts in Linux. I show two ways, the Terminal Duration: 4:49

Running Python Scripts Automatically in Linux

To run a Python script automatically in Linux, create a configuration file using crontab. Crontab is a tool used to schedule scripts or commands to run automatically. Here are the steps you need to follow:

1. Open the terminal and type “crontab -e” to open the crontab editor.
2. Add a shebang line at the top of your Python file to call the Python interpreter. For example, “#!/usr/bin/env python”.
3. Make the Python file executable using the chmod command. For example, “chmod +x path/to/your/script.py”.
4. Add a line to the crontab file to specify when and how often the script should run. For example, “0 0 * * * path/to/your/script.py”.

Here is an example of a crontab file that runs a Python script every day at midnight:

0 0 * * * path/to/your/script.py 

Running Python Scripts in Windows

To run Python scripts in Windows, users can use the Windows Terminal or PowerShell. Here are the steps you need to follow:

1. Open the Windows Terminal or PowerShell and navigate to the directory where the script is located.
2. Type “python” followed by the file name to run the script.
3. Users can also run Python scripts from the command line, IDLE, or by creating a batch file.

Best Practices for Python Programming

best practices for python programming include writing clean and readable code and using comments to explain the code. Here are some additional best practices:

1. Use the /usr/bin/env method instead of a fixed path to play nicely with virtualenv.
2. Use Vim or IDLE as text editors for Python scripts.
3. Use virtualenv to create isolated Python environments to avoid version conflicts.

Additional code samples that can be helpful for running Python scripts in Linux

In Python , for example, run python file using python code code example

In Python , in particular, run linux command using python code sample

import subprocess subprocess.call("command1") subprocess.call(["command1", "arg1", "arg2"])

In Python , how to run linux command in python code sample

import os cmd = 'your command here' os.system(cmd) 

In Python , Shell script to run python code example

In the file job.sh, put this #!/bin/sh python python_script.py Execute this command to make the script runnable for you : chmod u+x job.sh Run it : ./job.sh

Conclusion

In conclusion, the ability to run Python scripts in Linux and execute Linux commands in Python is a valuable skill for developers and system administrators. By following the steps outlined in this article, users can run Python scripts from the terminal or command line, execute Linux commands in their Python code, and automate Python scripts in Linux. Additionally, users can follow best practices for python programming to write clean and readable code, and use helpful resources to aid them in their Python programming journey.

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How to run python script on terminal (ubuntu)?

I’m new with python, I’ve been learning for a few weeks. However now I’ve just changed my OS and I’m now using ubuntu and I can’t run any script on my terminal. I made sure to have the #!/usr/bin/env python but when I go to the terminal and type, for example python test.py the terminal shows an error message like this

I will just add a smal precision, if you use #!/usr/bin/env python you can just type ./test.py to execute your script as Terminal will take account of your header and use python to launch the script. But before you have to change execution permission by doing chmod +x test.py . I understand it can be a bit special for a beginner but you will appreciate this in the future 😉

5 Answers 5

python: can’t open file ‘test.py’: [Errno 2] No such file or directory

Means that the file «test.py» doesn’t exist. (Or, it does, but it isn’t in the current working directory.)

I must save the file in any specific folder to make it run on terminal?

No, it can be where ever you want. However, if you just say, «test.py», you’ll need to be in the directory containing test.py.

Your terminal (actually, the shell in the terminal) has a concept of «Current working directory», which is what directory (folder) it is currently «in».

Thus, if you type something like:

test.py needs to be in the current working directory. In Linux, you can change the current working directory with cd . You might want a tutorial if you’re new. (Note that the first hit on that search for me is this YouTube video. The author in the video is using a Mac, but both Mac and Linux use bash for a shell, so it should apply to you.)

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