我的 Python 应用程序中的 Readline() 代码无法正常工作.为什么?

Question

我正在用python3.8.3和pyqt5构建一个应用程序。这是我代码的一部分：

def logupd(self):
users=open('NeveshtarUsers.txt', 'w')
users.write('Username: ')
users.write(self.user2.text())
users.write(' Password: ')
users.write(self.pass2.text())
users.write('.n')
users.write('Name: ')
users.write(self.name.text())
users.write('.n')
users.write('....................n')
self.no.setText('Loggind up has succesed. Please Login')
with open('NeveshtarUsers.txt') as file:
print('salam')
data = file.readlines()
print(data)

当我调用此代码时，输出为：

salam
[]

为什么数据为空？怎么了？

Answer 1

我认为问题不在于关闭以写入模式打开的文件

def logupd(self):
users=open('NeveshtarUsers.txt', 'w')
users.write('Username: ')
users.write(self.user2.text())
users.write(' Password: ')
users.write(self.pass2.text())
users.write('.n')
users.write('Name: ')
users.write(self.name.text())
users.write('.n')
users.write('....................n')
self.no.setText('Loggind up has succesed. Please Login')
# close the file that is opened in write , the text will get updated to the system's memory 
# only when the file is closed 
users.close()
with open('NeveshtarUsers.txt') as file:
print('salam')
data = file.readlines()
print(data)