Question

我一直在开发银行应用程序。我创建了登录/注册系统，其中每个用户都显示为txt文件。每个txt文件包含4行：登录名，密码，安全码，等等。我正在努力创建第四行。在我现有的代码中，给定的存款写在exisitng值旁边。是否可以读取以txt格式编写的字符串行，以便将其添加到给定的存款余额中，然后显示一个值？另外，第四行的默认值为0，它是一个字符串。

        self.balance = int(self.balance) + self.amt
        file=open(self.name, "a+")    # <----- Creates line in user's file.
        file.write(int(self.balance))
        messagebox.showinfo("balance","You have deposit: "+str(self.balance))


file=open(self.username_info, "w") <------ All user s are created as txt file

file.write(self.username_info+"\n") 

file.write(self.password_info+"\n")   

file.write(self.code_info+"\n")

file.write(self.cash)

Answer 1

with open("info","r") as fd:
    username,password,code,cash= [i.strip() for i in fd if len(i.strip())>1]

Answer 2

如果文件以“ r”模式打开，则您可以像这样balance = file.readlines()[3]读取余额存款，然后使用此变量执行所需的任何操作，然后重写四行。

以“写模式”打开文件可确保不附加任何数据。一切都被覆盖而不是修改，但是由于只有4行，所以没关系。

# Open the file, read its content, close the file.
file = open(file_name, "r")
lines = file.readlines()
file.close()

# Get the interesting info from the stored lines.
login = lines[0].rstrip() # <- add .rstrip() here if you want to get rid of the spaces and line feeds.
password = lines[1].rstrip()
security_code = lines[2].rstrip()
balance = int(lines[3]) # <- notice the int() for conversion.

# Do something on the balance, for example:
balance += deposit

# Open the file and write back the 4 lines, with the 4th modified.
file = open(file_name, "w")
file.write(login + "\n") 
file.write(password + "\n")   
file.write(security_code + "\n")
file.write(str(balance) + "\n")
file.close()

如果您有兴趣，这里是一个更紧凑的版本：

# Open the file, read its content, close the file.
with open(file_name, "r") as file:
    lines = file.readlines()

# Open the file and write back the 4 lines, with the 4th modified.
with open(file_name, "w") as file:
    file.write(lines[0])
    file.write(lines[1])  
    file.write(lines[2])
    file.write("%d \n" %(int(lines[3])+deposit))

如何在读取前清除字符串并将str转换为int

2 个答案: