Python 使用库、标准库、第三方库及综合案例实操

import math
import json
from pathlib import path

# 数学计算
import math
print(math.sqrt(16))
# 随机数
import random
print(random.randint(1, 10))
# 日期时间
from datetime import datetime
print(datetime.now())
# json 数据
import json
data = json.loads('{"name": "tom"}')
print(data["name"])
# 文件路径
from pathlib import path
print(path.cwd())

import math
print(math.sqrt(9))

from math import sqrt
print(sqrt(9))

import json       # 标准库
import requests   # 第三方库，通常需要先安装

import math
print(dir(math))
help(math.sqrt)

print(math.__doc__)

import [模块名]

import math
result = math.sqrt(16)
print(result)  # 4.0

模块名.功能名

import math
import random
import datetime

import math, random

import datetime as dt
now = dt.datetime.now()
print(now)

import numpy as np
import pandas as pd

from math import sqrt
result = sqrt(25)
print(result)  # 5.0

from math import sqrt, pi
print(sqrt(9))
print(pi)

from math import *

import math

from math import sqrt

def add(a, b):
    return a + b

import tools
result = tools.add(3, 5)
print(result)  # 8

from tools import add
print(add(3, 5))

import 模块名

import datetime
date1 = datetime.datetime(2016, 2, 14)
date2 = datetime.datetime(2026, 7, 18)
print(date2 - date1)

class solution(object):
    def reversemessage(self, message):
        tokens = message.split()
        tokens.reverse()
        return ' '.join(tokens)

class solution(object):
    def rotatestring(self, s, goal):
        return len(s) == len(goal) and goal in s + s

class solution(object):
    def countprefixes(self, words, s):
        res = 0
        for word in words:
            if s.startswith(word):
                res += 1
        return res

import os
inputpath = input('请输入待搜索路径: ')
pattern = input('请输入待搜索关键词: ')
for dirpath, dirnames, filenames in os.walk(inputpath):
for f in filenames:
if pattern in f:
print(f'{dirpath}/{f}')

import requests
import numpy
import pandas

pip install requests

python -m pip install requests

import requests

import requests
response = requests.get("https://example.com")
print(response.status_code)

import numpy as np
numbers = np.array([1, 2, 3, 4])
print(numbers)

import math       # 标准库，不需要额外安装
import requests   # 第三方库，通常需要先安装

pip list

pip show requests

pip uninstall requests

pip install --upgrade requests

查找库 → pip 安装 → import 导入 → 调用功能

pip install qrcode

import qrcode
img = qrcode.make('hello world')
img.save('qrcode.png')

pip install xlrd==1.2.0

import xlrd
# 1. 打开 xlsx 文件
xlsx = xlrd.open_workbook('文件地址链接')
# 2. 获取 0 号标签页. (当前只有一个标签页)
table = xlsx.sheet_by_index(0)
# 3. 获取总行数
nrows = table.nrows
# 4. 遍历数据
count = 0
total = 0
for i in range(1, nrows):
# 使用 cell_value(row, col) 获取到指定坐标单元格的值.
classid = table.cell_value(i, 1)
if classid == 101:
total += table.cell_value(i, 2)
count += 1
print(f'平均分: {total / count}')

pip install pynput==1.6.8
pip install playsound==1.2.2

from pynput import keyboard
from playsound import playsound
count = 0
def on_release(key):
print(key)
global count
count += 1
if count % 10 == 0:
playsound('xxx.mp3')
listener = keyboard.listener(
on_release=on_release)
listener.start()
listener.join()

from pynput import keyboard
from playsound import playsound
from threading import thread
count = 0
def on_release(key):
print(key)
global count
count += 1
if count % 10 == 0:
t = thread(target=playsound, args=('ding.mp3',))
t.start()
#playsound('xxx.mp3')
listener = keyboard.listener(
on_release=on_release)
listener.start()
listener.join()

# 使用列表表示所有的学生
students = []
def main():
"""
程序的入口函数
"""
print('+--------------------------+')
print('| 欢迎来带学生管理系统! |')
print('+--------------------------+')
while true:
choice = menu()
if choice == 0:
sys.exit()
if choice == 1:
insert()
elif choice == 2:
show()
elif choice == 3:
find()
elif choice == 4:
delete()
else:
print('您的输入有误! 请重新输入!')
main()

def menu():
"""
显示程序菜单
"""
print(" 1. 新增学生信息")
print(" 2. 显示所有同学信息")
print(" 3. 根据名字查找学生信息")
print(" 4. 删除学生信息")
print(" 0. 退出程序")
choice = input(" 请输入您的选择: ")
return int(choice)

def insert():
print("[新增学生] 开始!")
studentid = input("请输入学生的学号: ")
name = input("请输入学生的姓名: ")
gender = input("请输入学生的性别: ")
if gender not in ('男', '女'):
print("性别不符合要求! 新增学生失败!")
return
classname = input("请输入学生的班级: ")
# 使用一个字典表示学生信息
student = {
'studentid': studentid,
'name': name,
'gender': gender,
'classname': classname
}
# 把字典添加到学生列表中
global students
students.append(student)
print("[新增学生] 完毕!")

def show():
print("[显示学生] 开始!")
for s in students:
print(f"
[{s['studentid']}]\t{s['name']}\t{s['gender']}\t{s['classname']}")
print(f"[显示学生] 完毕! 共显示了 {len(students)} 条记录!")

def find():
print("[查找学生] 开始!")
name = input("请输入要查找的同学姓名: ")
count = 0
for s in students:
if name == s['name']:
print(f"
[{s['studentid']}]\t{s['name']}\t{s['gender']}\t{s['classname']}")
count += 1
print(f"[查找学生] 完毕! 共查找到 {count} 条记录!")

def delete():
print("[删除学生] 开始!")
studentid = input("请输入要删除的同学学号: ")
count = 0
for s in students:
if studentid == s['studentid']:
print(f"删除 {s['name']} 同学的信息!")
students.remove(s)
count += 1
print(f"[删除学生] 完毕! 共删除 {count} 条记录!")

学号\t名字\t性别\t班级
学号\t名字\t性别\t班级
学号\t名字\t性别\t班级

def save():
"""
存档函数
"""
with open('xxx.txt', 'w') as f:
for s in students:
f.write(f"
{s['studentid']}\t{s['name']}\t{s['gender']}\t{s['classname']}\n")
print(f"[存档成功] 共存储了 {len(students)} 条记录!")

# 执行存档
save()

def load():
"""
读档函数
"""
# 如果存档文件不存在, 则跳过读档环节
if not os.path.exists('d:/record.txt'):
return
# 先清空全局变量里的数据
global students
students = []
with open('xxx.txt', 'r') as f:
for line in f:
# 去除末尾的换行符
line = line.strip()
tokens = line.split('\t')
if len(tokens) < 4:
print(f"文件格式有误! line={line}")
continue
student = {
'studentid': tokens[0],
'name': tokens[1],
'gender': tokens[2],
'classname': tokens[3]
}
students.append(student)
print(f"[读档成功] 共读取了 {len(students)} 条记录!")

load()

pip install pyinstaller

pyinstall -f 学生管理系统.py