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Raising | Error Handling
Mastering Python: Annotations, Errors and Environment

Raising

Let's learn how to raise an error.

Errors can be raised using the raise keyword:

The TypeError in the example above was raised without a message.

To output an error message, you can pass a string inside the parentheses () after the error object:

Task

You have implemented the perimeter() function that returns the triangle perimeter. This function receives the sides of a triangle (a, b, and c). You need to add error raising to this function.

  1. All received sides should be int or float data type. In another case, the function should raise the TypeError with the message "All sides should be int or float type".
  2. In a triangle, all sides should have a length greater than 0. In other cases, the function should raise the ValueError with the message "All sides should be greater than 0".
  3. In a triangle, the sum of two sides must always be greater than the third side (otherwise, the two sides would not reach each other through the third side). Therefore, if one of the received sides is greater than the sum of the other two, the program must raise the ValueError with the message "It's not a triangle".

Everything was clear?

Section 3. Chapter 3
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course content

Course Content

Mastering Python: Annotations, Errors and Environment

Raising

Let's learn how to raise an error.

Errors can be raised using the raise keyword:

The TypeError in the example above was raised without a message.

To output an error message, you can pass a string inside the parentheses () after the error object:

Task

You have implemented the perimeter() function that returns the triangle perimeter. This function receives the sides of a triangle (a, b, and c). You need to add error raising to this function.

  1. All received sides should be int or float data type. In another case, the function should raise the TypeError with the message "All sides should be int or float type".
  2. In a triangle, all sides should have a length greater than 0. In other cases, the function should raise the ValueError with the message "All sides should be greater than 0".
  3. In a triangle, the sum of two sides must always be greater than the third side (otherwise, the two sides would not reach each other through the third side). Therefore, if one of the received sides is greater than the sum of the other two, the program must raise the ValueError with the message "It's not a triangle".

Everything was clear?

Section 3. Chapter 3
toggle bottom row
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