第 7 章 · 实战项目串讲

import pandas as pd
import matplotlib.pyplot as plt

df = pd.read_csv("scores.csv")
subjects = ["数学", "英语", "语文"]

# 1) 统计
print(df[subjects].mean().round(1))      # 各科平均分
print("最高总分：", df[subjects].sum(axis=1).max())

# 2) 画柱状图
df[subjects].mean().plot(kind="bar", color=["#b04a2c", "#5e7a46", "#b06a24"])
plt.title("各科平均分")
plt.savefig("avg.png")                    # 保存图片
print("报告图已生成：avg.png")

import csv, io, statistics

csv_text = """姓名,数学,英语,语文
小明,90,85,88
小红,82,79,91
小刚,80,86,85
"""

def build_report(text, subjects, ndigits=1):
    rows = list(csv.DictReader(io.StringIO(text)))
    print("分析科目：", subjects)
    for s in subjects:
        scores = [int(r[s]) for r in rows]
        print(f"  {s} 平均分：{round(statistics.mean(scores), ndigits)}")
    best = max(rows, key=lambda r: sum(int(r[s]) for s in subjects))
    print("总分最高：", best["姓名"])

# 改这里就能换分析的科目 / 小数位数
build_report(csv_text, ["数学", "英语", "语文"], ndigits=1)

import os, shutil, re, datetime

def organize(folder):
    for name in os.listdir(folder):
        src = os.path.join(folder, name)
        if not os.path.isfile(src):
            continue
        try:
            m = re.search(r"(\d{4})-(\d{2})", name)
            ym = m.group(1) + "-" + m.group(2) if m else \
                 datetime.datetime.fromtimestamp(os.path.getmtime(src)).strftime("%Y-%m")
            dest = os.path.join(folder, ym)
            os.makedirs(dest, exist_ok=True)
            shutil.move(src, os.path.join(dest, name))
            print("已整理", name, "→", ym)
        except Exception as e:      # 单个文件出错不影响整体
            print("跳过", name, "原因：", e)

if __name__ == "__main__":
    organize("downloads")

import os, shutil, re, tempfile

def organize(folder, dry_run=True):
    for name in sorted(os.listdir(folder)):
        src = os.path.join(folder, name)
        if not os.path.isfile(src):
            continue
        m = re.search(r"(\d{4})-(\d{2})", name)
        ym = m.group(1) + "-" + m.group(2) if m else "未知月份"
        dest = os.path.join(folder, ym)
        if dry_run:
            print("将移动（预览）:", name, "→", ym)
        else:
            os.makedirs(dest, exist_ok=True)
            shutil.move(src, os.path.join(dest, name))
            print("已移动:", name, "→", ym)

# 建一个临时测试目录
tmp = tempfile.mkdtemp()
for f in ["报告-2026-09.pdf", "照片-2026-08.jpg", "笔记.txt"]:
    open(os.path.join(tmp, f), "w").close()

print("=== 预览模式（dry_run=True，不动文件）===")
organize(tmp, dry_run=True)

import requests, re

def fetch_links(url):
    try:
        r = requests.get(url, timeout=5)
        r.raise_for_status()              # 非 200 直接抛异常
        html = r.text
        title = re.search(r"", html, re.S)
        links = re.findall(r'href="(.*?)"', html)
        return (title.group(1).strip() if title else "无标题", links)
    except Exception as e:
        return ("抓取失败", [str(e)])

t, links = fetch_links("https://example.com")
print("标题：", t)
print("前 5 个链接：", links[:5])

import re

html = '''
<html><head><title>示例学院官网</title></head>
<body>
  <a href="https://a.edu/index">首页</a>
  <a href="/news/1">新闻</a>
  <img src="logo.png">
</body></html>
'''

title = re.search(r"<title>(.*?)</title>", html, re.S)
links = re.findall(r'href="(.*?)"', html)
print("标题：", title.group(1).strip() if title else "无标题")
print("提取到的链接：")
for i, u in enumerate(links, 1):
    print(f"  {i}. {u}")