To calculate the square root of a number in Python, you can make use of the `math`

module. The `math`

module provides a function called `sqrt()`

which can be used to calculate the square root. Here’s how you can do it:

import math number = 16 square_root = math.sqrt(number) print(square_root)

In this example, we first import the `math`

module using the `import`

statement. Then, we define a variable called `number`

and assign it a value of `16`

. We then use the `math.sqrt()`

function to calculate the square root of `number`

and store the result in a variable called `square_root`

. Finally, we print the value of `square_root`

using the `print()`

function.

The output of the above code will be:

4.0

This means that the square root of 16 is 4.

### Handling Negative Numbers

The `math.sqrt()`

function can also handle negative numbers. When you pass a negative number to the function, it will return a complex number representing the square root of that negative number. Here’s an example:

import math number = -9 square_root = math.sqrt(number) print(square_root)

The output of the above code will be:

(1.8369701987210297e-16+3j)

In this case, the square root of -9 is a complex number with a very small real part and an imaginary part.

### Alternative Method: Using Exponentiation

Another way to calculate the square root of a number in Python is by using exponentiation. You can raise a number to the power of `0.5`

to find its square root. Here’s an example:

number = 16 square_root = number ** 0.5 print(square_root)

The output of the above code will be the same as before:

4.0

This method can be useful if you don’t want to use the `math`

module or if you’re working in an environment where the `math`

module is not available.

### Best Practices

When calculating square roots in Python, it is important to keep the following best practices in mind:

1. Import the `math`

module: Before using the `sqrt()`

function, make sure to import the `math`

module using the `import`

statement.

2. Handle exceptions: When dealing with user input or variables that can potentially be negative, consider using exception handling to handle cases where the square root is not defined. For example:

import math number = float(input("Enter a number: ")) try: square_root = math.sqrt(number) print(square_root) except ValueError: print("Invalid input. Cannot calculate square root of a negative number.")

In this example, we use the `float()`

function to convert the user input to a floating-point number. Then, we use a `try-except`

block to catch the `ValueError`

that may occur if the user enters a negative number. If a negative number is entered, an error message is displayed instead of trying to calculate the square root.

3. Use meaningful variable names: When writing code, it is good practice to use variable names that accurately describe the purpose of the variable. For example, instead of using `number`

, you could use `input_number`

or `value_to_calculate`

.

4. Document your code: If you are writing code that will be used by others or reviewed by a team, it is important to add comments or docstrings to explain the purpose and behavior of your code. This can make it easier for others to understand and maintain your code.