Introduction to Common Python Standard Library Modules

os – provides a way to use operating system functionality such as reading/writing files, directory operations, etc.

import os
print(os.getcwd())  # 获取当前工作目录

sys – accesses variables and functions closely related to the Python interpreter.

import sys
print(sys.version)  # 打印Python版本信息

datetime – handles dates and times.

from datetime import datetime
print(datetime.now())  # 当前日期和时间

math – provides support for mathematical operations, from basic numeric handling to advanced functions.

import math
print(math.pi)  # 圆周率π

random – generates random numbers.

import random
print(random.randint(1, 10))  # 随机整数

json – encodes and decodes JSON data.

import json
data = {'key': 'value'}
json_str = json.dumps(data)
print(json_str)  # JSON字符串

re – regular expression operations, supporting complex string search and replace.

import re
result = re.search('world', 'Hello world!')
if result:
    print("找到匹配:", result.group())

sqlite3 – used to interact with SQLite databases.

import sqlite3
conn = sqlite3.connect(':memory:')
print("内存数据库已创建")

argparse – used to write user‑friendly command‑line interfaces; it can automatically generate help and usage information and parse command‑line arguments.

import argparse
parser = argparse.ArgumentParser(description='命令行示例')
parser.add_argument('--name', type=str, help='你的名字')
args = parser.parse_args()
print(f"你好, {args.name}")

logging – supports a flexible logging system, allowing you to record information during program execution.

import logging
logging.basicConfig(level=logging.INFO)
logging.info("这是一个日志信息")

collections – provides additional data structures such as namedtuple, deque, Counter, etc.

from collections import Counter
count = Counter(['a', 'b', 'a', 'c'])
print(count)  # 统计元素出现次数