基于已有Go/Java/C的开发经验，Python可以在很短时间内掌握基础语法和核心概念。以下是学习要点和完整Demo：
1 语法
1.1 数据类型
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# 变量和数据类型（动态类型） name = "Python" # 字符串 version = 3.9 # 整数 rating = 9.5 # 浮点数 is_awesome = True # 布尔值 nothing = None # 空值 # 集合类型 fruits = ["apple", "banana", "orange"] # 列表（可变） coordinates = (40.7128, -74.0060) # 元组（不可变） person = {"name": "John", "age": 30} # 字典 unique_numbers = {1, 2, 3, 3, 4} # 集合（自动去重） # 类型注解（可选，类似Go/Java） def greet(name: str) -> str: return f"Hello, {name}" |
1.2 控制流
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# 条件语句 age = 25 if age < 18: print("Minor") elif 18 <= age < 65: print("Adult") else: print("Senior") # 循环 for i in range(5): # 0到4 print(i) for fruit in fruits: # 遍历列表 print(fruit) # 列表推导式（Python特色） squares = [x**2 for x in range(10) if x % 2 == 0] |
1.3 函数和类
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# 函数定义 def calculate_area(length, width=1): # 默认参数 """计算面积""" # 文档字符串 return length * width # 类定义 class Person: def __init__(self, name, age): # 构造函数 self.name = name self.age = age def introduce(self): return f"I'm {self.name}, {self.age} years old" # 继承 class Student(Person): def __init__(self, name, age, student_id): super().__init__(name, age) self.student_id = student_id |
2 综合Demo：任务管理系统
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""" 任务管理系统 - 展示Python核心特性 """ from typing import List, Dict, Optional from datetime import datetime, timedelta import json class Task: """任务类""" def __init__(self, title: str, description: str = "", priority: int = 1): self.title = title self.description = description self.priority = priority # 1-5, 5最高 self.created_at = datetime.now() self.completed = False self.tags: List[str] = [] def complete(self) -> None: """标记任务为完成""" self.completed = True def add_tag(self, tag: str) -> None: """添加标签""" if tag not in self.tags: self.tags.append(tag) def __str__(self) -> str: status = "✓" if self.completed else "◯" return f"[{status}] {self.title} (优先级: {self.priority})" def to_dict(self) -> Dict: """转换为字典（用于JSON序列化）""" return { "title": self.title, "description": self.description, "priority": self.priority, "created_at": self.created_at.isoformat(), "completed": self.completed, "tags": self.tags } class TaskManager: """任务管理器""" def __init__(self): self.tasks: List[Task] = [] def add_task(self, title: str, **kwargs) -> Task: """添加任务，支持关键字参数""" task = Task(title, **kwargs) self.tasks.append(task) return task def get_pending_tasks(self) -> List[Task]: """获取未完成的任务""" return [task for task in self.tasks if not task.completed] def get_high_priority_tasks(self, threshold: int = 3) -> List[Task]: """获取高优先级任务""" return [ task for task in self.tasks if task.priority >= threshold and not task.completed ] def complete_task(self, title: str) -> bool: """根据标题完成任务""" for task in self.tasks: if task.title == title and not task.completed: task.complete() return True return False def get_tasks_by_tag(self, tag: str) -> List[Task]: """根据标签筛选任务""" return [task for task in self.tasks if tag in task.tags] def get_task_statistics(self) -> Dict: """获取任务统计信息""" total = len(self.tasks) completed = sum(1 for task in self.tasks if task.completed) pending = total - completed # 使用字典推导式 priority_dist = { f"priority_{i}": sum(1 for task in self.tasks if task.priority == i) for i in range(1, 6) } return { "total": total, "completed": completed, "pending": pending, "completion_rate": completed / total if total > 0 else 0, "priority_distribution": priority_dist } def save_to_file(self, filename: str) -> None: """保存任务到文件""" data = [task.to_dict() for task in self.tasks] with open(filename, 'w', encoding='utf-8') as f: json.dump(data, f, ensure_ascii=False, indent=2) def load_from_file(self, filename: str) -> None: """从文件加载任务""" try: with open(filename, 'r', encoding='utf-8') as f: data = json.load(f) self.tasks = [] for item in data: task = Task( item["title"], item["description"], item["priority"] ) task.completed = item["completed"] task.tags = item["tags"] self.tasks.append(task) except FileNotFoundError: print("文件不存在，创建新的任务列表") def main(): """主函数 - 演示使用""" manager = TaskManager() # 添加任务 task1 = manager.add_task( "学习Python基础", description="掌握Python核心语法", priority=5 ) task1.add_tag("学习") task1.add_tag("编程") manager.add_task("写项目文档", priority=3).add_tag("工作") manager.add_task("购买 groceries", priority=2).add_tag("生活") |
