1. **Hello World:**
```python
print("Hello, World!")
```
2. **变量和数据类型:**
```python
name = "John"
age = 25
height = 1.75
is_student = False
```
3. **条件语句:**
```python
if age >= 18:
print("You are an adult.")
else:
print("You are a minor.")
```
4. **循环:**
```python
for i in range(5):
print(i)
```
5. **函数:**
```python
def greet(name):
print("Hello, " + name + "!")
greet("Alice")
```
6. **列表和循环:**
```python
numbers = [1, 2, 3, 4, 5]
for num in numbers:
print(num)
```
7. **文件读写:**
```python
with open("example.txt", "w") as file:
file.write("Hello, File!")
with open("example.txt", "r") as file:
content = file.read()
print(content)
```
8. **异常处理:**
```python
try:
result = 10 / 0
except ZeroDivisionError:
print("Cannot divide by zero.")
```
9. **字典:**
```python
person = {"name": "Alice", "age": 30, "city": "Wonderland"}
print(person["name"])
```
10. **日期和时间:**
```python
from datetime import datetime
current_time = datetime.now()
print(current_time)
```
11. **正则表达式:**
```python
import re
text = "The price is $20."
match = re.search(r'\$(\d+)', text)
if match:
print("Price:", match.group(1))
```
12. **JSON 解析:**
```python
import json
data = '{"name": "Bob", "age": 25}'
parsed_data = json.loads(data)
print(parsed_data["name"])
```
13. **爬虫基础:**
```python
import requests
response = requests.get("https://www.example.com")
print(response.text)
```
14. **多线程:**
```python
import threading
import time
def print_numbers():
for i in range(5):
time.sleep(1)
print(i)
thread = threading.Thread(target=print_numbers)
thread.start()
```
15. **GUI 界面:**
```python
from tkinter import Tk, Label
root = Tk()
label = Label(root, text="Hello, GUI!")
label.pack()
root.mainloop()
```
16. **类和对象:**
```python
class Dog:
def __init__(self, name, age):
self.name = name
self.age = age
def bark(self):
print("Woof!")
my_dog = Dog("Buddy", 3)
print(my_dog.name)
my_dog.bark()
```
17. **Lambda 表达式:**
```python
square = lambda x: x ** 2
print(square(5))
```
18. **Map 和 Filter:**
```python
numbers = [1, 2, 3, 4, 5]
squared_numbers = list(map(lambda x: x**2, numbers))
even_numbers = list(filter(lambda x: x % 2 == 0, numbers))
print(squared_numbers)
print(even_numbers)
```
19. **列表推导式:**
```python
squares = [x**2 for x in range(5)]
even_squares = [x**2 for x in range(5) if x % 2 == 0]
print(squares)
print(even_squares)
```
20. **使用 Pillow 处理图像:**
```python
from PIL import Image
img = Image.open("image.jpg")
img.show()
```
21. **NumPy 数组操作:**
```python
import numpy as np
array = np.array([[1, 2, 3], [4, 5, 6]])
transposed = np.transpose(array)
print(array)
print(transposed)
```
22. **Pandas 数据分析:**
```python
import pandas as pd
data = {'Name': ['Alice', 'Bob', 'Charlie'],
'Age': [25, 30, 22]}
df = pd.DataFrame(data)
print(df)
```
23. **Matplotlib 绘图:**
```python
import matplotlib.pyplot as plt
x = [1, 2, 3, 4, 5]
y = [2, 4, 6, 8, 10]
plt.plot(x, y)
plt.xlabel('X-axis')
plt.ylabel('Y-axis')
plt.title('Simple Plot')
plt.show()
```
24. **使用 Flask 构建 Web 应用:**
```python
from flask import Flask
app = Flask(__name__)
@app.route('/')
def hello():
return 'Hello, Flask!'
if __name__ == '__main__':
app.run(debug=True)
```
25. **使用 SQLAlchemy 进行数据库操作:**
```python
from sqlalchemy import create_engine, Column, Integer, String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
engine = create_engine('sqlite:///example.db', echo=True)
Base = declarative_base()
class User(Base):
__tablename__ = 'users'
id = Column(Integer, primary_key=True)
name = Column(String)
age = Column(Integer)
Base.metadata.create_all(engine)
# 使用 session 进行数据库操作
```
26. **使用 Flask 实现 RESTful API:**
```python
from flask import Flask, jsonify
app = Flask(__name__)
@app.route('/api/greet/<name>', methods=['GET'])
def greet(name):
message = {'greeting': f'Hello, {name}!'}
return jsonify(message)
if __name__ == '__main__':
app.run(debug=True)
```
27. **异步编程 with Asyncio:**
```python
import asyncio
async def hello():
print("Hello, ")
await asyncio.sleep(1)
print("Async World!")
asyncio.run(hello())
```
28. **发送电子邮件:**
```python
import smtplib
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
sender_email = "your_email@gmail.com"
receiver_email = "recipient_email@gmail.com"
password = "your_email_password"
message = MIMEMultipart()
message['From'] = sender_email
message['To'] = receiver_email
message['Subject'] = "Test Email"
body = "This is a test email."
message.attach(MIMEText(body, 'plain'))
with smtplib.SMTP('smtp.gmail.com', 587) as server:
server.starttls()
server.login(sender_email, password)
server.send_message(message)
```
29. **使用 Flask 进行用户认证:**
```python
from flask import Flask, request, jsonify
from flask_jwt_extended import JWTManager, create_access_token, jwt_required, get_jwt_identity
app = Flask(__name__)
app.config['JWT_SECRET_KEY'] = 'super-secret' # Change this in a real application
jwt = JWTManager(app)
@app.route('/login', methods=['POST'])
def login():
username = request.json.get('username', None)
password = request.json.get('password', None)
if username != 'user' or password != 'pass':
return jsonify({"msg": "Bad username or password"}), 401
access_token = create_access_token(identity=username)
return jsonify(access_token=access_token), 200
@app.route('/protected', methods=['GET'])
@jwt_required()
def protected():
current_user = get_jwt_identity()
return jsonify(logged_in_as=current_user), 200
if __name__ == '__main__':
app.run(debug=True)
```
30. **使用 TensorFlow 进行简单的机器学习:**
```python
import tensorflow as tf
from tensorflow.keras.models import Sequential
from tensorflow.keras.layers import Dense
# Create a simple model
model = Sequential([
Dense(10, activation='relu', input_shape=(784,)),
Dense(10, activation='softmax')
])
model.compile(optimizer='adam', loss='sparse_categorical_crossentropy', metrics=['accuracy'])
```
31. **使用 OpenCV 处理图像:**
```python
import cv2
# 读取图像
image = cv2.imread('image.jpg')
# 将图像转换为灰度
gray_image = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
# 显示图像
cv2.imshow('Original Image', image)
cv2.imshow('Gray Image', gray_image)
cv2.waitKey(0)
cv2.destroyAllWindows()
```
32. **使用 Selenium 进行 Web 自动化:**
```python
from selenium import webdriver
driver = webdriver.Chrome()
# 打开网页
driver.get('https://www.example.com')
# 查找元素并操作
search_box = driver.find_element('name', 'q')
search_box.send_keys('Python')
search_box.submit()
# 关闭浏览器
driver.quit()
```
33. **使用 Pytest 进行单元测试:**
```python
def add(a, b):
return a + b
def test_add():
assert add(2, 3) == 5
assert add(-1, 1) == 0
assert add(0, 0) == 0
```
34. **使用 Requests 发送 HTTP 请求:**
```python
import requests
response = requests.get('https://www.example.com')
print(response.status_code)
print(response.text)
```
35. **使用 Flask-WTF 创建表单:**
```python
from flask import Flask, render_template
from flask_wtf import FlaskForm
from wtforms import StringField, SubmitField
app = Flask(__name__)
app.config['SECRET_KEY'] = 'secret_key'
class MyForm(FlaskForm):
name = StringField('Name')
submit = SubmitField('Submit')
@app.route('/', methods=['GET', 'POST'])
def index():
form = MyForm()
if form.validate_on_submit():
return f'Hello, {form.name.data}!'
return render_template('index.html', form=form)
if __name__ == '__main__':
app.run(debug=True)
```
36. **使用 Flask-SocketIO 实现实时通信:**
```python
from flask import Flask, render_template
from flask_socketio import SocketIO
app = Flask(__name__)
app.config['SECRET_KEY'] = 'secret_key'
socketio = SocketIO(app)
@app.route('/')
def index():
return render_template('index.html')
@socketio.on('message')
def handle_message(msg):
print('Message:', msg)
socketio.emit('message', msg)
if __name__ == '__main__':
socketio.run(app, debug=True)
```
37. **使用 Flask-RESTful 创建 RESTful API:**
```python
from flask import Flask
from flask_restful import Resource, Api
app = Flask(__name__)
api = Api(app)
class HelloWorld(Resource):
def get(self):
return {'hello': 'world'}
api.add_resource(HelloWorld, '/')
if __name__ == '__main__':
app.run(debug=True)
```
38. **使用 Flask-Migrate 进行数据库迁移:**
```python
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///example.db'
db = SQLAlchemy(app)
migrate = Migrate(app, db)
class User(db.Model):
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(80), unique=True, nullable=False)
@app.route('/')
def index():
users = User.query.all()
return ', '.join([user.username for user in users])
if __name__ == '__main__':
app.run(debug=True)
```
39. **使用 FastAPI 创建现代 Web API:**
```python
from fastapi import FastAPI
app = FastAPI()
@app.get("/")
def read_root():
return {"Hello": "World"}
@app.get("/items/{item_id}")
def read_item(item_id: int, query_param: str = None):
return {"item_id": item_id, "query_param": query_param}
```
40. **使用 Flask-Login 进行用户认证:**
```python
from flask import Flask, render_template, redirect, url_for
from flask_login import LoginManager, UserMixin, login_user, login_required, logout_user
app = Flask(__name__)
app.config['SECRET_KEY'] = 'secret_key'
login_manager = LoginManager(app)
class User(UserMixin):
def __init__(self, user_id):
self.id = user_id
@login_manager.user_loader
def load_user(user_id):
return User(user_id)
@app.route('/login/<user_id>')
def login(user_id):
user = User(user_id)
login_user(user)
return redirect(url_for('protected'))
@app.route('/protected')
@login_required
def protected():
return f'Hello, {current_user.id}!'
@app.route('/logout')
@login_required
def logout():
logout_user()
return 'Logged out successfully.'
if __name__ == '__main__':
app.run(debug=True)
```
41. **使用 PyTorch 进行简单的深度学习:**
```python
import torch
import torch.nn as nn
import torch.optim as optim
# 定义一个简单的神经网络
class SimpleNet(nn.Module):
def __init__(self):
super(SimpleNet, self).__init__()
self.fc = nn.Linear(10, 1)
def forward(self, x):
return self.fc(x)
# 创建模型、损失函数和优化器
model = SimpleNet()
criterion = nn.MSELoss()
optimizer = optim.SGD(model.parameters(), lr=0.01)
# 训练模型
for epoch in range(100):
inputs = torch.randn(100, 10) # 随机生成输入
targets = torch.randn(100, 1) # 随机生成目标值
optimizer.zero_grad()
outputs = model(inputs)
loss = criterion(outputs, targets)
loss.backward()
optimizer.step()
```
42. **使用 Flask-Security 实现用户认证和授权:**
```python
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_security import Security, SQLAlchemyUserDatastore, UserMixin, RoleMixin
app = Flask(__name__)
app.config['SECRET_KEY'] = 'secret_key'
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///example.db'
db = SQLAlchemy(app)
# 定义用户和角色模型
roles_users = db.Table('roles_users',
db.Column('user_id', db.Integer(), db.ForeignKey('user.id')),
db.Column('role_id', db.Integer(), db.ForeignKey('role.id'))
)
class Role(db.Model, RoleMixin):
id = db.Column(db.Integer(), primary_key=True)
name = db.Column(db.String(80), unique=True)
class User(db.Model, UserMixin):
id = db.Column(db.Integer, primary_key=True)
email = db.Column(db.String(255), unique=True)
password = db.Column(db.String(255))
roles = db.relationship('Role', secondary=roles_users, backref=db.backref('users', lazy='dynamic'))
user_datastore = SQLAlchemyUserDatastore(db, User, Role)
security = Security(app, user_datastore)
if __name__ == '__main__':
app.run(debug=True)
```
43. **使用 Pandas 处理时间序列数据:**
```python
import pandas as pd
# 创建一个简单的时间序列
date_rng = pd.date_range(start='2022-01-01', end='2022-01-10', freq='D')
time_series = pd.Series(range(len(date_rng)), index=date_rng)
# 汇总每周的数据
weekly_sum = time_series.resample('W').sum()
```
44. **使用 Flask-JWT-Extended 实现 JSON Web Token (JWT) 认证:**
```python
from flask import Flask
from flask_jwt_extended import JWTManager, jwt_required, create_access_token
app = Flask(__name__)
app.config['JWT_SECRET_KEY'] = 'secret_key'
jwt = JWTManager(app)
@app.route('/login', methods=['POST'])
def login():
username = request.json.get('username', None)
password = request.json.get('password', None)
if username != 'user' or password != 'pass':
return jsonify({"msg": "Bad username or password"}), 401
access_token = create_access_token(identity=username)
return jsonify(access_token=access_token), 200
@app.route('/protected', methods=['GET'])
@jwt_required()
def protected():
current_user = get_jwt_identity()
return jsonify(logged_in_as=current_user), 200
if __name__ == '__main__':
app.run(debug=True)
```
45. **使用 Flask-RESTful 配合 SQLAlchemy 构建 RESTful API:**
```python
from flask import Flask
from flask_restful import Resource, Api, reqparse
from flask_sqlalchemy import SQLAlchemy
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///example.db'
db = SQLAlchemy(app)
api = Api(app)
# 定义数据模型
class Todo(db.Model):
id = db.Column(db.Integer, primary_key=True)
task = db.Column(db.String(120))
# 创建请求解析器
parser = reqparse.RequestParser()
parser.add_argument('task')
class TodoResource(Resource):
def get(self, todo_id):
todo = Todo.query.filter_by(id=todo_id).first()
return {'task': todo.task}
def put(self, todo_id):
args = parser.parse_args()
todo = Todo.query.filter_by(id=todo_id).first()
todo.task = args['task']
db.session.commit()
return {'task': todo.task}
def delete(self, todo_id):
todo = Todo.query.filter_by(id=todo_id).first()
db.session.delete(todo)
db.session.commit()
return {'result': True}
api.add_resource(TodoResource, '/todos/<int:todo_id>')
if __name__ == '__main__':
db.create_all()
app.run(debug=True)
```
46. **使用 Flask-SocketIO 实现实时多人聊天室:**
```python
from flask import Flask, render_template
from flask_socketio import SocketIO, emit
app = Flask(__name__)
app.config['SECRET_KEY'] = 'secret_key'
socketio = SocketIO(app)
@app.route('/')
def index():
return render_template('chat.html')
@socketio.on('message')
def handle_message(msg):
emit('message', msg, broadcast=True)
if __name__ == '__main__':
socketio.run(app, debug=True)
```
47. **使用 Flask-Caching 进行缓存:**
```python
from flask import Flask
from flask_caching import Cache
app = Flask(__name__)
cache = Cache(app, config={'CACHE_TYPE': 'simple'})
@app.route('/')
@cache.cached(timeout=60)
def cached_route():
return 'This route is cached for 60 seconds.'
if __name__ == '__main__':
app.run(debug=True)
```
48. **使用 Flask-Moment 处理日期和时间:**
```python
from flask import Flask, render_template
from flask_moment import Moment
app = Flask(__name__)
moment = Moment(app)
@app.route('/')
def index():
return render_template('index.html')
if __name__ == '__main__':
app.run(debug=True)
```
49. **使用 Flask-RESTful 配合 Marshmallow 进行数据序列化:**
```python
from flask import Flask
from flask_restful import Resource, Api
from flask_marshmallow import Marshmallow
app = Flask(__name__)
api = Api(app)
ma = Marshmallow(app)
class Person:
def __init__(self, name, age):
self.name = name
self.age = age
class PersonSchema(ma.Schema):
class Meta:
fields = ('name', 'age')
person_schema = PersonSchema()
class PersonResource(Resource):
def get(self, name):
person = Person(name=name, age=30)
return person_schema.dump(person)
api.add_resource(PersonResource, '/person/<string:name>')
if __name__ == '__main__':
app.run(debug=True)
```
50. **使用 Flask-Migrate 和 Flask-Script 进行数据库迁移和管理:**
```python
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_script import Manager
from flask_migrate import Migrate, MigrateCommand
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///example.db'
db = SQLAlchemy(app)
migrate = Migrate(app, db)
manager = Manager(app)
manager.add_command('db', MigrateCommand)
class User(db.Model):
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(80), unique=True, nullable=False)
if __name__ == '__main__':
manager.run()
```
这些示例覆盖了更多主题，包括实时多人聊天室（使用 Flask-SocketIO）、缓存（使用 Flask-Caching）、处理日期和时间（使用 Flask-Moment）、数据序列化（使用 Flask-RESTful 和 Marshmallow）以及数据库迁移和管理（使用 Flask-Migrate 和 Flask-Script）。
