Python 30个常用的基础模块，提升开发效率

import os

# 获取当前工作目录
current_dir = os.getcwd()
print(f"当前目录: {current_dir}")

# 检查文件是否存在
if os.path.exists("example.txt"):
    print("文件存在")

# 遍历目录
for item in os.scandir('.'):
    print(f"{item.name} - 目录" if item.is_dir() else f"{item.name} - 文件")

import sys

# 获取Python版本信息
print(f"Python版本: {sys.version}")

# 查看模块搜索路径
print("模块搜索路径:")
for path in sys.path:
    print(f"  {path}")

# 程序退出
if len(sys.argv) < 2:
    print("缺少参数")
    sys.exit(1)

import platform

print(f"操作系统: {platform.system()}")
print(f"系统版本: {platform.release()}")
print(f"处理器架构: {platform.architecture()[0]}")

import json

# 复杂数据序列化
data = {
    "users": [
        {"name": "张三", "age": 25, "hobbies": ["阅读", "编程"]},
        {"name": "李四", "age": 30, "hobbies": ["音乐", "旅行"]}
    ]
}

# 美化输出
json_str = json.dumps(data, indent=2, ensure_ascii=False)
print(json_str)

# 从文件读取JSON
with open('data.json', 'w', encoding='utf-8') as f:
    json.dump(data, f, ensure_ascii=False)

import csv

# 写入CSV文件
headers = ['姓名', '年龄', '城市']
rows = [
    ['王五', 28, '北京'],
    ['赵六', 35, '上海'],
    ['孙七', 22, '广州']
]

with open('users.csv', 'w', newline='', encoding='utf-8') as f:
    writer = csv.writer(f)
    writer.writerow(headers)
    writer.writerows(rows)

# 使用DictReader读取
with open('users.csv', 'r', encoding='utf-8') as f:
    reader = csv.DictReader(f)
    for row in reader:
        print(f"{row['姓名']} - {row['年龄']}岁")

from collections import defaultdict, deque, namedtuple

# 命名元组
Person = namedtuple('Person', ['name', 'age', 'city'])
p1 = Person('张三', 25, '北京')
print(f"{p1.name} 来自 {p1.city}")

# 双端队列
dq = deque([1, 2, 3])
dq.appendleft(0)  # 左侧添加
dq.append(4)      # 右侧添加
print(list(dq))   # [0, 1, 2, 3, 4]

# 带默认值的字典
word_count = defaultdict(int)
text = "hello world hello python world"
for word in text.split():
    word_count[word] += 1
print(dict(word_count))

from datetime import datetime, date, timedelta

# 当前日期时间
now = datetime.now()
print(f"当前时间: {now}")

# 日期计算
today = date.today()
next_week = today + timedelta(days=7)
print(f"今天: {today}, 一周后: {next_week}")

# 格式化输出
formatted = now.strftime("%Y年%m月%d日 %H时%M分%S秒")
print(formatted)

import time

# 性能测试装饰器
def timer(func):
    def wrapper(*args, **kwargs):
        start = time.perf_counter()
        result = func(*args, **kwargs)
        end = time.perf_counter()
        print(f"{func.__name__} 执行时间: {end-start:.4f}秒")
        return result
    return wrapper

@timer
def slow_function():
    time.sleep(1)
    return "完成"

slow_function()

import math

# 常用数学计算
print(f"π的值: {math.pi}")
print(f"e的值: {math.e}")
print(f"2的平方根: {math.sqrt(2):.4f}")
print(f"5的阶乘: {math.factorial(5)}")

# 对数计算
print(f"以10为底100的对数: {math.log10(100)}")

import random

# 生成随机数据
random_numbers = [random.randint(1, 100) for _ in range(5)]
print(f"随机整数: {random_numbers}")

# 随机抽样
items = ['苹果', '香蕉', '橙子', '葡萄', '芒果']
sample = random.sample(items, 3)
print(f"随机样本: {sample}")

# 打乱顺序
random.shuffle(items)
print(f"打乱后: {items}")

from urllib.request import urlopen, Request
from urllib.parse import urlencode, quote

# 发送HTTP请求
def fetch_url(url):
    req = Request(url, headers={'User-Agent': 'Mozilla/5.0'})
    with urlopen(req) as response:
        content = response.read().decode('utf-8')
        return content[:200]  # 返回前200字符

# URL编码
search_term = "Python编程"
encoded = quote(search_term)
print(f"编码后: {encoded}")

import socket

# 创建TCP客户端
def tcp_client(host, port):
    client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    client.settimeout(5)
    
    try:
        client.connect((host, port))
        client.send(b"GET / HTTP/1.1\r\nHost: example.com\r\n\r\n")
        response = client.recv(1024)
        return response.decode('utf-8')
    except socket.timeout:
        return "连接超时"
    finally:
        client.close()

# 获取主机信息
hostname = socket.gethostname()
print(f"主机名: {hostname}")

import pickle

class User:
    def __init__(self, name, email):
        self.name = name
        self.email = email
    
    def __repr__(self):
        return f"User(name='{self.name}', email='{self.email}')"

# 序列化对象
users = [
    User('张三', 'zhang@example.com'),
    User('李四', 'li@example.com')
]

with open('users.pkl', 'wb') as f:
    pickle.dump(users, f)

# 反序列化
with open('users.pkl', 'rb') as f:
    loaded_users = pickle.load(f)
    print(loaded_users)

import sqlite3

def create_database():
    conn = sqlite3.connect('example.db')
    cursor = conn.cursor()
    
    # 创建表
    cursor.execute('''
        CREATE TABLE IF NOT EXISTS products (
            id INTEGER PRIMARY KEY,
            name TEXT NOT NULL,
            price REAL,
            stock INTEGER
        )
    ''')
    
    # 插入数据
    products = [
        ('笔记本电脑', 5999.99, 10),
        ('智能手机', 3999.50, 25),
        ('平板电脑', 2999.00, 15)
    ]
    
    cursor.executemany('INSERT INTO products (name, price, stock) VALUES (?, ?, ?)', products)
    conn.commit()
    
    # 查询数据
    cursor.execute('SELECT * FROM products WHERE price > 3000')
    for row in cursor.fetchall():
        print(f"产品: {row[1]}, 价格: {row[2]}")
    
    conn.close()

create_database()

import re

text = """
联系人信息:
张三: 138-1234-5678
李四: (021) 6234-5678
王五: +86 139 8765 4321
"""

# 提取手机号码
phone_pattern = r'(\d{3}[-\.\s]??\d{4}[-\.\s]??\d{4}|\(\d{3}\)\s*\d{3}[-\.\s]??\d{4})'
phones = re.findall(phone_pattern, text)
print("找到的电话号码:", phones)

# 邮箱验证
def validate_email(email):
    pattern = r'^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$'
    return bool(re.match(pattern, email))

print(validate_email("test@example.com"))  # True
print(validate_email("invalid.email"))     # False

import string

# 字符串常量
print(f"所有字母: {string.ascii_letters}")
print(f"数字: {string.digits}")
print(f"标点符号: {string.punctuation}")

# 模板字符串
template = string.Template('欢迎 $name 参加 $event 活动！')
message = template.substitute(name='张三', event='Python大会')
print(message)

import argparse

def main():
    parser = argparse.ArgumentParser(description='文件处理工具')
    parser.add_argument('input_file', help='输入文件路径')
    parser.add_argument('-o', '--output', help='输出文件路径')
    parser.add_argument('-v', '--verbose', action='store_true', help='详细输出')
    parser.add_argument('--count', type=int, default=1, help='处理次数')
    
    args = parser.parse_args()
    
    if args.verbose:
        print(f"处理文件: {args.input_file}")
        print(f"输出到: {args.output}")
        print(f"处理次数: {args.count}")

if __name__ == "__main__":
    main()

import logging

# 配置日志系统
logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
    handlers=[
        logging.FileHandler('app.log'),
        logging.StreamHandler()
    ]
)

logger = logging.getLogger('my_app')

def process_data(data):
    logger.info(f"开始处理数据，长度: {len(data)}")
    try:
        # 模拟数据处理
        result = len(data) * 2
        logger.debug(f"处理结果: {result}")
        return result
    except Exception as e:
        logger.error(f"处理数据时出错: {e}")
        raise

process_data("测试数据")

import hashlib

def hash_file(filename):
    """计算文件的SHA256哈希值"""
    hash_sha256 = hashlib.sha256()
    with open(filename, "rb") as f:
        for chunk in iter(lambda: f.read(4096), b""):
            hash_sha256.update(chunk)
    return hash_sha256.hexdigest()

def hash_password(password, salt=''):
    """密码哈希"""
    return hashlib.pbkdf2_hmac('sha256', password.encode(), salt.encode(), 100000).hex()

print(f"密码哈希: {hash_password('mypassword', 'salt')}")

import itertools

# 无限迭代器
counter = itertools.count(start=10, step=2)
print("计数器:", [next(counter) for _ in range(5)])

# 排列组合
letters = ['A', 'B', 'C']
combinations = list(itertools.combinations(letters, 2))
print("组合:", combinations)

# 分组操作
data = [1, 1, 2, 3, 3, 3, 4]
grouped = [(key, list(group)) for key, group in itertools.groupby(data)]
print("分组结果:", grouped)

from functools import lru_cache, partial

@lru_cache(maxsize=100)
def fibonacci(n):
    if n < 2:
        return n
    return fibonacci(n-1) + fibonacci(n-2)

from operator import itemgetter, attrgetter

data = [('张三', 25), ('李四', 30), ('王五', 20)]
sorted_data = sorted(data, key=itemgetter(1))

import glob

py_files = glob.glob('*.py')
print("Python文件:", py_files)

import shutil

# 复制文件树
shutil.copytree('source_dir', 'backup_dir')

import tempfile

with tempfile.NamedTemporaryFile() as tmp:    
tmp.write(b"临时数据")    
print(f"临时文件: {tmp.name}")

import zipfile

with zipfile.ZipFile('archive.zip', 'w') as zf:    
zf.write('file1.txt')

import configparser

config = configparser.ConfigParser()
config.read('config.ini')

from pathlib import Path

path = Path('example.txt')
print(f"文件扩展名: {path.suffix}")

import statistics

data = [1, 2, 3, 4, 5]
print(f"平均值: {statistics.mean(data)}")

import weakref

class Data:    
pass
obj = Data()
weak_obj = weakref.ref(obj)