如何保证Python代码质量，Python测试与调试方面的经验和心得

import unittest

class TestStringMethods(unittest.TestCase):
    def test_upper(self):
        self.assertEqual('hello'.upper(), 'HELLO')
    
    def test_isupper(self):
        self.assertTrue('HELLO'.isupper())
        self.assertFalse('Hello'.isupper())
    
    def test_split(self):
        s = 'hello world'
        self.assertEqual(s.split(), ['hello', 'world'])
        # 检查分割后的列表长度
        self.assertEqual(len(s.split()), 2)

if __name__ == '__main__':
    unittest.main()

def test_upper():
    assert 'hello'.upper() == 'HELLO'

def test_isupper():
    assert 'HELLO'.isupper()
    assert not 'Hello'.isupper()

def test_split():
    s = 'hello world'
    assert s.split() == ['hello', 'world']
    assert len(s.split()) == 2

# 安装coverage
pip install coverage

# 运行测试并测量覆盖率
coverage run -m pytest

# 查看覆盖率报告
coverage report

# 生成HTML覆盖率报告
coverage html

# calculator.py
def add(a, b):
    return a + b

def subtract(a, b):
    return a - b

def multiply(a, b):
    return a * b

def divide(a, b):
    if b == 0:
        raise ValueError("Cannot divide by zero")
    return a / b

# test_calculator.py
import unittest
from calculator import add, subtract, multiply, divide

class TestCalculator(unittest.TestCase):
    def test_add(self):
        self.assertEqual(add(1, 2), 3)
        self.assertEqual(add(-1, 1), 0)
        self.assertEqual(add(0, 0), 0)
    
    def test_subtract(self):
        self.assertEqual(subtract(5, 3), 2)
        self.assertEqual(subtract(1, 5), -4)
    
    def test_multiply(self):
        self.assertEqual(multiply(2, 3), 6)
        self.assertEqual(multiply(-1, 5), -5)
    
    def test_divide(self):
        self.assertEqual(divide(6, 2), 3)
        self.assertEqual(divide(5, 2), 2.5)
        with self.assertRaises(ValueError):
            divide(1, 0)

if __name__ == '__main__':
    unittest.main()

import unittest

class TestDatabase(unittest.TestCase):
    def setUp(self):
        # 设置测试环境
        self.db = {'users': []}
    
    def tearDown(self):
        # 清理测试环境
        self.db = None
    
    def test_add_user(self):
        self.db['users'].append({'id': 1, 'name': 'Alice'})
        self.assertEqual(len(self.db['users']), 1)
    
    def test_remove_user(self):
        self.db['users'].append({'id': 1, 'name': 'Alice'})
        self.db['users'].pop()
        self.assertEqual(len(self.db['users']), 0)

if __name__ == '__main__':
    unittest.main()

import unittest
from flask import Flask
from flask.testing import FlaskClient

app = Flask(__name__)

@app.route('/')
def index():
    return 'Hello, World!'

@app.route('/user/<name>')
def user(name):
    return f'Hello, {name}!'

class TestFlaskApp(unittest.TestCase):
    def setUp(self):
        app.config['TESTING'] = True
        self.client = app.test_client()
    
    def test_index(self):
        response = self.client.get('/')
        self.assertEqual(response.status_code, 200)
        self.assertIn(b'Hello, World!', response.data)
    
    def test_user(self):
        response = self.client.get('/user/Alice')
        self.assertEqual(response.status_code, 200)
        self.assertIn(b'Hello, Alice!', response.data)

if __name__ == '__main__':
    unittest.main()

def divide(a, b):
    print(f"Debug: a = {a}, b = {b}")
    if b == 0:
        print("Debug: Division by zero")
        raise ValueError("Cannot divide by zero")
    result = a / b
    print(f"Debug: result = {result}")
    return result

import pdb

def divide(a, b):
    pdb.set_trace()  # 设置断点
    if b == 0:
        raise ValueError("Cannot divide by zero")
    return a / b

divide(10, 2)

try:
    result = 10 / 0
except ZeroDivisionError as e:
    print(f"Error: {e}")
except Exception as e:
    print(f"Unexpected error: {e}")
else:
    print(f"Result: {result}")
finally:
    print("This block always executes")

class CustomError(Exception):
    pass

def validate_age(age):
    if age < 0:
        raise CustomError("Age cannot be negative")
    return age

try:
    validate_age(-5)
except CustomError as e:
    print(f"Error: {e}")