一、os.path

import os.path

print(os.path.abspath('day2.py'))  # 返回绝对路径
print(os.path.exists('a.txt'))  # 返回文件是否存在
print(os.path.join('D:\\Py file\\pythonProject', 'day2.py'))  # 将目录和文件名拼接起来
print(os.path.split('D:\\Py file\\pythonProject\\day2.py'))  # 将目录和文件拆分
print(os.path.splitext('day2.py'))  # 将文件名拆分
print(os.path.basename('D:\\Py file\\pythonProject\\day2.py'))  # 提取文件名
print(os.path.dirname('D:\\Py file\\pythonProject\\day2.py'))  # 提取目录
print(os.path.isdir('D:\\Py file\\pythonProject\\day2.py'))  # 判断是否是目录

获取当前目录下所有.py文件

import os.path

path = os.getcwd()
flist = os.listdir(path)
for i in flist:
    if i.endswith('.py'):
        print(i, end='\t')

os.walk(path)#返回一个可迭代对象，path中所有目录，文件

二、学生管理系统(写bug)

import os
import re


def menu():
    print('菜单')
    print('-------------------------------------------------------')
    print('1.录入学生信息')
    print('2.查找学生信息')
    print('3.删除学生信息')
    print('4.修改学生信息')
    print('5.统计学生总人数')
    print('6.显示所有学生信息')
    print('0.退出系统')
    print('------------------------------------------------------')


def insert():
    id = input('添加的学生id为:')
    name = input('学生姓名为：')
    english = int(input(name + '的英语成绩为：'))
    python = int(input(name + '的python成绩为：'))
    java = int(input(name + '的java成绩为：'))
    dict = {'id': id, 'name': name, 'english': english, 'python': python, 'java': java}
    with open('./student.txt', 'a') as fp:
        fp.write(str(dict) + '\n')
    answer = input('信息录入成功是否继续Y/N')
    if answer == 'y' or answer == 'Y':
        insert()
    else:
        pass


def show_student(lst):
    if len(lst) == 0:
        print('没有查询到学生信息')
        return
    format_title = '{:^6}\t{:^12}\t{:^8}\t{:^10}\t{:^10}\t{:^8}'
    print(format_title.format('ID', '姓名', '英语成绩', 'Python成绩', 'java成绩', '总成绩'))
    format_data = '{:^6}\t{:^12}\t{:^8}\t{:^10}\t{:^10}\t{:^8}'
    for dic in lst:
        print(format_data.format(dic.get('id'),
                                 dic.get('name'),
                                 dic.get('english'),
                                 dic.get('python'),
                                 dic.get('java'),
                                 int(dic.get('english')) + int(dic.get('python')) + int(dic.get('java'))
                                 ))


def search():
    while True:
        with open('./student.txt', 'r') as fp:
            res = fp.readlines()
        id = ''
        list = []
        name = ''
        if os.path.exists('./student.txt'):
            choice = int(input('按id查找请输入0，按姓名查找请按1:'))
            if choice in [0, 1]:
                if choice == 0:
                    id = str(input('请输入要查找的id：'))
                if choice == 1:
                    name = input('请输入要查找的学生姓名：')
                for item in res:
                    d = dict(eval(item))
                    if id != '':
                        if d['id'] == id:
                            list.append(d)
                    else:
                        if d['name'] == name:
                            list.append(d)
                if len(list) == 0:
                    print('没有查询到结果！')
                    answer = input(('是否继续Y/N'))
                    if answer == 'Y' or answer == 'y':
                        search()
                    else:
                        return
                else:
                    show_student(list)
                list = ''
                print('查询结束')
                answer = input(('是否继续Y/N'))
                if answer == 'Y' or answer == 'y':
                    search()
                else:
                    break
            else:
                print('选错了！')
                continue
        else:
            print('暂未保存学员信息!')
            return


def delete():
    while True:
        flag = False
        stu_id = input('请输入要删除的学生的ID:')
        if stu_id != '':
            with open('./student.txt', 'r') as fp:
                stu_all = fp.readlines()
            if stu_all:
                with open('./student.txt', 'w') as fp:
                    for item in stu_all:
                        a = dict(eval(item))
                        if a['id'] != stu_id:
                            fp.write(str(a) + '\n')
                        else:
                            flag = True
                    if flag:
                        print('id为' + stu_id + '的学生信息已删除！')
                    else:
                        print('没有id为：' + stu_id + '的学生数据')
            else:
                print('没有一条数据，先录入学生信息吧')
                insert()
                return
            show()
            answer = input(('是否继续Y/N'))
            if answer == 'Y' or answer == 'y':
                delete()
            else:
                break


def modify():
    list = []
    show()
    with open('./student.txt', 'r') as fp:
        stu_all = fp.readlines()
        id = input('请输入要修改的学员id：')
        for item in stu_all:
            a = dict(eval(item))
            list.append(a['id'])
            if a['id'] == id:
                print('找到该学生信息，可以修改了！')
                a['name'] = input('请输入姓名')
                a['english'] = input('请输入英语成绩')
                a['python'] = input('请输入python成绩')
                a['java'] = input('请输入java成绩')
                with open('./student.txt', 'w') as fp:
                    fp.write(str(a) + '\n')
                    fp.close()
                print('修改成功')
            else:
                with open('./student.txt', 'w') as fp1:
                    fp1.write(str(a) + '\n')
                    fp1.close()
        if list:
            if id not in list:
                print('没有此id对应学生信息，请重新输入')
                modify()
        else:
            print('没有数据，请添加！')
            insert()
            return

        answer = input(('是否继续修改Y/N'))
        if answer == 'Y' or answer == 'y':
            modify()
        else:
            return


def total():
    with open('./student.txt', 'r') as fp:
        res = fp.readlines()
        if len(res) > 0:
            print('共有{}名学生'.format(len(res)))
        else:
            print('还没有录入学生数据')


def show():
    stu_list = []
    with open('./student.txt', 'r') as fp:
        students = fp.readlines()
        for item in students:
            d = dict(eval(item))
            stu_list.append(d)
        if stu_list:
            show_student(stu_list)
        else:
            print('没有数据，录入一些吧！')


if __name__ == '__main__':
    while True:
        menu()
        choice = int(input('请输入您的选择：'))
        if choice in [0, 1, 2, 3, 4, 5, 6, 7]:
            if choice == 0:
                answer = input('您确定要退出系统吗？Y/N')
                if answer == 'Y' or answer == 'y':
                    print('拜拜了！')
                    break
                else:
                    continue
            elif choice == 1:
                insert()
            elif choice == 2:
                search()
            elif choice == 3:
                delete()
            elif choice == 4:
                modify()
            elif choice == 5:
                total()
            elif choice == 6:
                show()
        else:
            print('选择已有的功能！')
            continue