What are Python Command Line Arguments? Know everything here
As a professional Python developer, you might have heard about the Python command line arguments. The crucial place for user input handling and other data entry. It provides more interactivity and robust concepts with the program.
Here we will cover all the foremost concepts about the same. You will get the insight about how to run and how to read the command line arguments in Python.
Command-line Argument in Python Overview:
Command Line Arguments in Python are the input parameters which are passed to the script while execution. These arguments are specified after the name of the program.
A command line interface enables users to interact with software on their system. Numerous softwares have specific tasks that run and perform based on the words. The command line arguments are passed into a program through the CLkeyI by the user.
How to run command line interface in Python?
The argparse Python library is used for the process which is available in the standard library. You need to import the CLI arguments library into your code. This is simply done like any other Python import.
/* Import the library */
Import argparse
The next step will be ready to use. After importing the library you need to prepare your software to accept CLI arguments. It is done by making a few more changes.
/*Create the parser*/
parser = argparse.ArgumentParser()
This code will generate an instance of the argparse. There is a need for more information to operate in a meaningful way. The next will be adding an argument for the argument parser. It will acquire the input from the user.
/*Add an argument*/
parser.add_argument(‘– firstName’, type=str, required=True)
This line of code dictates a new argument for the parser. Now, the add_argument() method will take the three parameters. The code will create an argument called firstName. The second one is the type parameter and it will specify the type of data in the argument.
The last parameter will dictate if the argument is required for the software to run. It will only accept the boolean values i.e. true or false.
/*Parse the argument*/
args = parser.parse_args()
The line of code will command the program to check and parse the arguments. It will show an error if the required arguments are absent. Also, it will tell the user to incorporate arguments.
/*Print “Welcome” + the user input argument*/
print(‘Welcome,’, argos.firstName)
This code will instruct the program on what to do with the arguments.
How to read Python Command Line Arguments?
The command line argument can be differentiated into three main pieces. The first is the command itself and this invokes the process or runs the program.
Here we are telling Python to run the file named nameCreator.py. This will instruct the program to run and complete whatever tasks the program is meant to run.
You will get an error message when you run this code. It is due to the missing — firstName argument.
– – firstName Castiel
Here the bit of code will provide the argument which is needed by the program. It also passes the name Castiel as its value. Now look at the full line of code needed to run the program.
python welcome.py — name Castiel
