Python Coverage Library Entering Tutorial
Python Coverage Library Entering Tutorial
The Coverage library in Python is a powerful tool that helps developers understand the operation of the code and test coverage.This tutorial will introduce how to analyze the coverage of the Python code with the COVERAGE library and generate a corresponding report.
1. Install the COVERAGE library
First, we need to use PIP to install the COVERAGE library.Execute the following commands in the command line:
pip install coverage
2. Configure the COVERAGE library
Create a new folder for storing test code and configuration files.Create a file called `.coveragerc` in the new folder, and add the following in it:
[run]
source = .
This configuration file tells the directory where the code we want to analyze.
3. Write test code
Create a file called `Calculator.py` in a new folder for testing.In this file, we will define a simple calculator class and some test functions.The following is an example:
python
class Calculator:
def add(self, a, b):
return a + b
def test_calculator():
calculator = Calculator()
assert calculator.add(2, 3) == 5
assert calculator.add(5, 7) == 12
test_calculator()
4. Run test code
In the command line, run the test code with the COVERAGE and generate code coverage report.Execute the following command:
coverage run calculator.py
This will run the code in the `Calculator.py` file and collect the code running information.
5. Generate report
Execute the following commands to generate the COVERAGE report:
coverage report -m
This will generate a brief report to display the coverage of the code.Among them, a column of "statements" represents the number of sentences in the code, a column "MISS" represents the number of statements that are not running, and the "Cover" column represents the number of statements covered.
In addition, we can generate a coverage report in HTML format.Execute the following command:
coverage html
This will generate a folder called `htmlcov` in the current folder, which contains an HTML file that reports the coverage rate.
So far, you have learned how to use the COVERAGE library to analyze the coverage of Python code and generate reports.I hope this tutorial can help you better evaluate the quality and test coverage of the code.Happy Coding!
