In Python, we can pass arguments to the Python script while running it on the terminal. These arguments are referred to as **command-line arguments**.

# Syntax
```
python main.py argument1 argument2
```

In order to access these arguments, we need to import the `sys` library:

``` python
import sys
```

The **`sys.argv`** contains the list of command-line arguments.
**`len(sys.argv)`** is the number of total command-line arguments.



# Code
In the code below, press the run button and then try running this script:
<pre>
python main.py chocolate strawberry 34
</pre>

# necessary library to ensure command is read in terminal.
import sys

#sys.argv contains arguments which are input in the terminal.
print ('Number of arguments:',len(sys.argv))

# Arguments are printed as a list
print ('Arguments:', str(sys.argv))

print(sys.argv[0]) #will print main.py

import React from 'react';
import { shallow, configure } from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';

configure({ adapter: new Adapter() });

import HelloWorld from './app';

var TestResult = function() {
    this.succeeded = false;
    this.reason = "";
    this.input = "";
    this.expected_output = "";
    this.actual_output = "";
}

export const executeTests = function() {

  var results = [];

  result = new TestResult();
  result.input = 'HelloWorld Component';
  result.expected_output = "span containing text 'Hello World'"

  let wrapper = shallow(<HelloWorld />);

  // Call your Challenge function here.

  let type = wrapper.type();
  let testSuccessful = true;
  let failureReason;

  if (type !== 'span') {
    testSuccessful = false;
    failureReason = "You need to render exactly one span HTML element";
  } else if (wrapper.props().children != "Hello World") {
     testSuccessful = false;
     failureReason = "You have rendered wrong message in your span element";
  }

  result.actual_output = wrapper.html();

  if (testSuccessful) {
    result.succeeded = true;
    result.reason = "Succeeded"
  } else {
    result.succeeded = false;
    result.reason = failureReason;
  }

  results.push(result);

  return results;
}


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The `len(sys.argv)` function returns the number of arguments. In our case, it returns `4` because we have passed four arguments:

1. `main.py`
2. chocolate
3. strawberry
4. 34 

> Without the `sys` library, this will give an error. 

Moreover, since this is a list, all these items can be accessed using list indices. For example, sys.argv[0] is `main.py`, sys.argv[1] is `chocolate`, and so on.

python3.tar.gz

Command-line​ arguments in Python

Python's sys.argv retrieves command-line arguments as a list, enabling argument parsing for scripts.

Command-line​ arguments in Python

Syntax

Code

Command-line arguments in Python