Python Command Line Arguments

Command line arguments are the parameters passed to the program during runtime. These parameters can be used by the program to perform specific actions or to modify its behavior.

Syntax

import sys

arguments = sys.argv

Example

import sys

arguments = sys.argv
print("Number of arguments:", len(arguments))
print("The arguments are:", str(arguments))

Output

$ python example.py arg1 arg2 arg3
Number of arguments: 4
The arguments are: ['example.py', 'arg1', 'arg2', 'arg3']

Explanation

In the above example, we have imported the sys module to access the argv variable. The argv variable is a list that contains all the command line arguments passed to the program. The first element of the list is always the name of the script itself.

We then print the length of the argv list to get the total number of arguments passed. We also print the entire argv list to show all the arguments passed to the program.

Use

Command line arguments are useful when we want to pass certain parameters to the program during runtime. This can be used to modify the behavior of the program depending on the arguments passed.

For example, if we have a program that reads a file and performs some operations on it, we can pass the filename as a command line argument. This reduces the need for user input and makes the program more automated.

Important Points

• Command line arguments are passed to the program during runtime.
• The sys.argv variable is a list that contains all the command line arguments passed to the program.
• The first element of the list is always the name of the script itself.
• Command line arguments are useful when we want to pass certain parameters to the program during runtime.

Summary

In this tutorial, we learned about command line arguments in Python. We saw how to access the command line arguments using the sys.argv variable and how to use them in our programs. Command line arguments are a useful feature that allows us to pass parameters to the program during runtime, making it more flexible and automated.