Hi there! In this quest, we're going to make a special Python helper called is_positive. This function will tell us if a number is greater than zero.
After we make our is_positive function, we'll learn how to write our own tests to make sure it works just right!
Now it's your turn to write the code! We need to make the is_positive function inside validator.py work.
Remember, a function is like a mini-program that does a specific job. Our is_positive function needs to take a number and tell us if it's positive (greater than zero) or not.
Here are some common ways to compare numbers in Python:
| Operator | Meaning | Example | Result |
|---|---|---|---|
== | Is equal to | 5 == 5 | True |
!= | Is not equal to | 5 != 3 | True |
> | Is greater than | 7 > 4 | True |
< | Is less than | 2 < 8 | True |
>= | Is greater than or equal to | 5 >= 5 | True |
<= | Is less than or equal to | 3 <= 1 | False |
Your task is to complete the is_positive function so it correctly checks if the number it receives is positive.
Now that you've started your is_positive function, it's time to write your own tests! This is a very important step because it helps you make sure your code works correctly.
Create a new file called test_validator.py in the same folder as your validator.py file.
Inside test_validator.py, you'll write test functions that check if your is_positive function gives the right answers. Here are some ideas for tests you should write:
is_positive(7) gives True and is_positive(100) gives True.is_positive(-5) gives False and is_positive(-1) gives False.is_positive(0) should give False.Remember to use assert to check if your function's answer matches what you expect!
# Example of a test function structure
import pytest # You'll need this if you use pytest.approx()
from validator import is_positive # This brings your is_positive function into the test file
def test_example_case():
# Call your function and check the result
assert is_positive(some_number) == expected_answer
Once you've written your tests, save the test_validator.py file. You're doing great!
Now that you've written your is_positive function and created your own tests in test_validator.py, let's run the tests to see if everything is working correctly!
Open your terminal and type this command:
pytest module-1.1/blueprint-6/quest-30
What you should see:
If all your tests show ✅, it means your is_positive function is working perfectly and your tests are doing a great job of checking it!
Now, let's review your code with your mentor. Be ready to talk about:
is_positive function.test_validator.py file.is_positive function.This document provides a quick reference for defining Python functions and writing basic tests using pytest.
A function is a block of code that performs a specific task. You define a function using the def keyword.
def function_name(parameter1, parameter2):
"""
This is a docstring. It explains what the function does.
Args:
parameter1: Description of the first parameter.
parameter2: Description of the second parameter.
Returns:
Description of the value the function returns.
"""
# Function body starts here, indented
# Code to perform the task
result = parameter1 + parameter2
return result # Use return to send a value back
def: Keyword to start a function definition.function_name: Choose a descriptive name.(parameter1, parameter2): Input values the function accepts. Can be zero or more.:: Marks the end of the function header."""..."""): Explains the function's purpose, arguments (Args), and return value (Returns). Good practice for documentation.return: Sends a value back from the function. If return is not used, the function returns None by default.
Testing helps verify that your code works as expected. pytest is a framework for writing and running tests in Python.
test_ or ending with _test.py.test_.
A test function calls the code you want to test and uses assert statements to check if the results are correct.
# Example test function structure
def test_something():
# Call the function you are testing
actual_result = your_function(input_value)
# Use assert to check if the actual result matches the expected result
assert actual_result == expected_result
def test_...: Defines a test function. pytest finds and runs functions named this way.assert condition: Checks if condition is True. If it's False, the test fails.
You can include multiple assert statements within a single test function to check different inputs or cases for the same function.
# Example test function with multiple assertions
def test_example_function():
# Test case 1: Positive input
assert example_function(5) == 25
# Test case 2: Negative input
assert example_function(-3) == 9
# Test case 3: Zero input
assert example_function(0) == 0
This approach helps ensure your function handles various situations correctly. If any assert fails, the test function stops and is marked as failed.
Navigate to your project directory in the terminal and run the command:
pytest
pytest will discover and run your test files and functions, reporting the results (PASSED, FAILED, etc.).
