操作文件 - 51天 - 在线学python100天

记录#

今天学习文件的读写操作。
比较特别的意思是将数组或字典写入到文件的时候，需要使用 str () 函数把这种数据转为字符串。
那再读取的时候，就需要用 eval () 函数把字符串转为动态可执行的代码。
今天这节课刚开始的时候有点迷迷糊糊，在 eval () 的使用上纠结了很久。直到在练习今天编码的时候才明白其中的逻辑，为什么要 str 和 eval。
还是有一点，写文件和 RAM 有什么关系？这节课 RAM 的用法或知识点在什么地方体现了？我还是不明白。
今天的练习是对 45 的编码进行完善，增加写文件和读文件的操作。第一次运行代码会报错，光头大哥说明天解决这个问题，哈哈哈！

CODE#

import os

print("🌟Life Organizer🌟")
print()
todolist = []
todoinfo = []
f = open("to.do", "r")
todolist = eval(f.read())
f.close


def todoprint():
  for row in todolist:
    for name in row:
      print(f"{name: ^10}", end=" | ")
    print()


select = "again"
while True:
  os.system("clear")
  if select == "again":
    print("Menu: ")
    print("1: Add ")
    print("2: Remove ")
    print("3: View ")
    print("4: Edit ")
    menu = input("")
    if menu.strip().lower()[0] == "a":
      task = input("What is the task? > ")
      due = input("When is it due by? > ")
      priority = input("What is the priority? > ")
      todoinfo = [task, due, priority]
      todolist.append(todoinfo)
      print("Thanks, this task has been added.")
      todoprint()
    elif menu.strip().lower()[0] == "r":
      name = input("Which one do you want remove? > ")
      for row in todolist:
        if name in row:
          todolist.remove(row)
          print("Thanks, this task has been removed.")
        else:
          print(f"{name} is not in the todolist")
    elif menu.strip().lower()[0] == "v":
      todoprint()
    elif menu.strip().lower()[0] == "e":
      name = input("Which one do you want remove? > ")
      for row in todolist:
        if name in row:
          todolist.remove(row)
          print("Thanks, this task has been removed.")
        else:
          print(f"{name} is not in the todolist")
      task = input("What is the task? > ")
      due = input("When is it due by? > ")
      priority = input("What is the priority? > ")
      todoinfo = [task, due, priority]
      todolist.append(todoinfo)
      print("Thanks, this task has been added.")
      todoprint()

    f = open("to.do", "w")
    f.write(str(todolist))
    f.close()

  elif select == "quit":
    break

  select = input("Do you want to see the menu again or quit? ")