python之函數練習

練習題

修改個人信息程序

在一個文件裏存多個人的個人信息，如以下

username password  age position department 
alex     abc123    24   Engineer   IT
rain     df2@432    25   Teacher   Teching
....

1.輸入用戶名密碼，正確後登錄系統 ，打印

1. 修改個人信息
2. 打印個人信息
3. 修改密碼

2.每個選項寫一個方法

3.登錄時輸錯3次退出程序

練習題答案

def print_personal_info(account_dic,username):
    """
    print user info 
    :param account_dic: all account's data 
    :param username: username 
    :return: None
    """
    person_data = account_dic[username]
    info = '''
    ------------------
    Name:   %s
    Age :   %s
    Job :   %s
    Dept:   %s
    Phone:  %s
    ------------------
    ''' %(person_data[1],
          person_data[2],
          person_data[3],
          person_data[4],
          person_data[5],
          )

    print(info)


def save_back_to_file(account_dic):
    """
    把account dic 轉成字符串格式 ，寫回文件 
    :param account_dic: 
    :return: 
    """
    f.seek(0) #回到文件頭
    f.truncate() #清空原文件
    for k in account_dic:
        row = ",".join(account_dic[k])
        f.write("%s\n"%row)

    f.flush()


def change_personal_info(account_dic,username):
    """
    change user info ,思路如下
    1. 把這個人的每個信息打印出來， 讓其選擇改哪個字段，用戶選擇了的數字，正好是字段的索引，這樣直接 把字段找出來改掉就可以了
    2. 改完後，還要把這個新數據重新寫回到account.txt，由於改完後的新數據 是dict類型，還需把dict轉成字符串後，再寫回硬盤 

    :param account_dic: all account's data 
    :param username: username 
    :return: None
    """
    person_data = account_dic[username]
    print("person data:",person_data)
    column_names = ['Username','Password','Name','Age','Job','Dept','Phone']
    for index,k in enumerate(person_data):
        if index >1: #0 is username and 1 is password
            print("%s.  %s: %s" %( index, column_names[index],k)  )

    choice = input("[select column id to change]:").strip()
    if choice.isdigit():
        choice = int(choice)
        if choice > 0 and choice < len(person_data): #index不能超出列表長度邊界
            column_data = person_data[choice] #拿到要修改的數據
            print("current value>:",column_data)
            new_val = input("new value>:").strip()
            if new_val:#不爲空
                person_data[choice] = new_val
                print(person_data)

                save_back_to_file(account_dic) #改完寫回文件
            else:
                print("不能爲空。。。")



account_file = "account.txt"
f = open(account_file,"r+")
raw_data = f.readlines()
accounts = {}
#把賬戶數據從文件裏讀書來，變成dict,這樣後面就好查詢了
for line in raw_data:
    line = line.strip()
    if not  line.startswith("#"):
        items = line.split(",")
        accounts[items[0]] = items


menu = '''
1. 打印個人信息
2. 修改個人信息
3. 修改密碼
'''

count = 0
while count <3:
    username = input("Username:").strip()
    password = input("Password:").strip()
    if username in accounts:
        if password == accounts[username][1]: #
            print("welcome %s ".center(50,'-') % username )
            while True: #使用戶可以一直停留在這一層
                print(menu)
                user_choice = input(">>>").strip()
                if user_choice.isdigit():
                    user_choice = int(user_choice)
                    if user_choice == 1:
                        print_personal_info(accounts,username)
                    elif user_choice == 2:
                        change_personal_info(accounts,username)

                elif user_choice == 'q':
                    exit("bye.")

        else:
            print("Wrong username or password!")
    else:
        print("Username does not exist.")

    count += 1

else:
    print("Too many attempts.")