1.工作流程

2.模擬自動存取款機的操作

代碼如下：

import msvcrt, sys, os#定義用星號隱藏密碼輸入的函數def psw_input():  li = []  while True:    ch = msvcrt.getch()    #回車    if ch == b'/r':      msvcrt.putch(b'/n')      break    #退格    elif ch == b'/x08':      if li:        li.pop()        msvcrt.putch(b'/b')        msvcrt.putch(b' ')        msvcrt.putch(b'/b')    #Esc    elif ch == b'/x1b':      break    else:      li.append(ch)      msvcrt.putch(b'*')  return li#定義CSDN銀行ATM歡迎界面的函數def ATM():  '''  CSDN銀行ATM歡迎界面的函數  '''  print("="*14,"Bank of CSDN","="*14,"/n")  print("{:^42}".format("ATM"),"/n")  print("="*14,"Bank of CSDN","="*14,"/n")#CSDN銀行用戶列表信息，用戶信息包含：姓名、余額、密碼（6位）、銀行卡號（19位）user_list = [{"name":"張 三","balance":10000,"password":"000000","numbers":"0000000000000000000"},{"name":"李 四","balance":20000,"password":"111111","numbers":"1111111111111111111"},{"name":"王 五","balance":30000,"password":"222222","numbers":"2222222222222222222"}]#定義驗證銀行卡號與密碼匹配的函數def check(user_name,user_password):  '''  驗證銀行卡號與密碼匹配的函數  '''   for i in range(len(user_list)):    if user_name == user_list[i]["numbers"] and user_password == user_list[i]["password"]:      return i #銀行卡號與密碼匹配則返回該用戶在ATM系統內的ID值，否則返回None值#定義用戶登錄成功后操作界面的函數def interface():  '''  用戶登錄成功后操作界面的函數  '''  print("="*14,"用戶操作界面","="*14,"/n")  print("{0:2} {1:12} {2:12} {3:12}".format(" ","1. 查詢","2. 取款","3. 存款"),"/n")  print("{0:2} {1:10} {2:12}".format(" ","4. 修改密碼","5. 退出"),"/n")  print("="*42,"/n")#定義用戶查詢信息的函數def inquire(user_id):  '''  用戶查詢信息的函數  '''  print("="*14,"賬號查詢界面","="*14,"/n")  print("|{0:<4}|{1:<18}|{2:<9}|/n".format("賬戶名","卡號","余額(RMB)"))  print("|{0:<5}|{1:<20}|{2:<11}|/n".format(user_list[user_id]["name"],user_list[user_id]["numbers"],user_list[user_id]["balance"]))#定義用戶取款的函數def withdrawal(amount):  '''  用戶取款的函數  '''  i = user_list[user_id]["balance"]-int(amount)  if i>=0:    user_list[user_id]["balance"]-=int(amount)  else:    print("賬戶余額不足/n")#定義用戶存款的函數def deposit(amount):  '''  用戶存款的函數  '''  user_list[user_id]["balance"]+=int(amount)#定義用戶修改密碼的函數def change_password(old_password,new_password1,new_password2):  '''  用戶修改密碼的函數  '''  if old_password == user_list[user_id]["password"]:    if new_password1 == new_password2:      user_list[user_id]["password"] = new_password1      print("新密碼修改成功/n")      return 1    else:      print("修改密碼失敗，您2次輸入的新密碼不一致/n")      return 2  else:    print("舊密碼輸入錯誤/n")    return 0#用戶登錄界面，輸入銀行卡號和密碼chance = 3 #允許3次用戶名或密碼輸入錯誤while True:  ATM()  user_name = input("請輸入您的銀行卡卡號：")  print("")  print("請輸入您的銀行卡密碼:", end=' ', flush=True)  user_password = b''.join(psw_input()).decode()  print("")  user_id = check(user_name,user_password)#驗證銀行卡號與密碼是否匹配  if user_id != None:    print("登錄成功/n")    while True:      interface()      key_word = input("請輸入操作選項：")      print("")      if key_word == "1":        inquire(user_id)        input("按任意鍵返回上一級目錄:")        print("")      elif key_word == "2":        print("="*14,"賬號取款界面","="*14,"/n")        amount = input("請輸入取款金額：")        print("")        withdrawal(amount)        inquire(user_id)        input("按任意鍵返回上一級目錄:")        print("")      elif key_word == "3":        print("="*14,"賬號存款界面","="*14,"/n")        amount = input("請輸入存款金額：")        print("")        deposit(amount)        inquire(user_id)        input("按任意鍵返回上一級目錄:")        print("")      elif key_word == "4":        print("="*14,"密碼管理界面","="*14,"/n")        print("請輸入舊密碼:", end=' ', flush=True)        old_password = b''.join(psw_input()).decode()        print("")        print("請輸入新密碼:", end=' ', flush=True)        new_password1 = b''.join(psw_input()).decode()        print("")        print("請再次輸入新密碼:", end=' ', flush=True)        new_password2 = b''.join(psw_input()).decode()        print("")                save = change_password(old_password,new_password1,new_password2)        #如何檢測到舊密碼輸入有誤，將直接退出        if save == 0:          break      elif key_word == "5":        print("="*14,"歡迎下次光臨","="*14,"/n")        break      else:        print("="*14,"沒有該選項","="*14,"/n")  else:    if chance > 1:           print("用戶名或密碼錯誤，您還有",chance-1,"次機會，請重新輸入/n")      chance -= 1    else:      print("對不起，您輸入用戶名或密碼錯誤已達3次")      break