Python comes with a built-in
sys module which stands for System-Specific and using this module we can indulge with the Python interpreter and some of its variables. In Python core development we often use the sys module to deal with the operating systems and python interpreter itself. Here in this article we will go through the sys module argv property and discuss how to parse command-line options and arguments with this sys.argv property.
What are command line Arguments in Python?
Like the concept of function argument or parameters in Python, we have command-line arguments for command line terminal or Python shell.
When we execute a python script using terminal or shell, such as by using the Command prompt of windows and terminal of macOS, we use the python command followed by the script name.
But Python also allows us to pass arguments while we execute any python script at the terminal, and these arguments are known a Command Line Arguments in Python
C:\>python script.py arg1 arg2 arg3
script.py is the python script and
arg1, arg2, and
arg3 are Command-Line arguments of Python.
Python sys.argv property with Examples
By far we have learned that what are Command Line Arguments in Python and how can we pass them while executing a Python program in a command terminal. Now let’s discuss how can we access them within a Python program.
sys.argv property allows us to grab those Command line arguments as a list of strings values. The sys.argv is a Python list that gets automatically created when we execute the Python script using the system terminal or command prompt for windows.
import sys print(sys.argv)
Execute on terminal
C:\Users\tsmehra\dev >python example.py ['example.py']
And when we execute our python script the name of the script becomes the first element of the sys.argv list.
Pass Python Command-Line arguments and access them using sys.argv
As we know that
sys.argv is a list of Python Command-line Arguments and by default, its first element is the script name itself. And it takes all the command lines argument as a string value.
import sys print(sys.argv)
Execute at terminal
C:\Users\tsmehra\dev>python example.py first second third 1 2 3 ['example.py', 'first', 'second', 'third', '1', '2', '3']
Why do we use the Command Line Arguments in Python?
The only purpose of command-line arguments to pass additional information about the program execution at runtime. Using this we can give inputs to the program when we execute it.
import sys print("The file name is:", sys.argv) name = sys.argv last_name = sys.argv print("This file is executed by:",name, last_name )
C:\Users\tsmehra\dev>python example.py Ram Kumar The file name is: example.py This file is executed by: Ram Kumar
Here in this article, you learned how can you access the Command Line Arguments in Python using the
argv property. The Python
sys.argv is a list that gets automatically created when the Python script is executed and by default, the script name becomes the first value of this list. All the other command-line arguments are stored as string values to the
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