我目前正在尝试使用python和PyQt4(而不是Qt Designer)创建程序.我创建了一个登录类(QDialog)和一个Homepage类(QMainWindow).但是,因为我的程序将包含大量页面(通过程序导航将很大)我想知道如何在QMainWindow中切换布局,而不是不断创建新窗口并关闭旧窗口.例如,我将MainWindow('HomePage')布局设置为登录后的默认屏幕,然后在MainWindow中有一个子类,允许我导航到用户设置(或任何其他页面).而不是创建一个新窗口并关闭MainWindow,有没有办法让我将MainWindow布局交换到用户设置布局？(道歉,如果这没有意义,我对PyQt不熟悉).示例代码如下所示(V.Basic代码)

-------------------------------------------------- --------------------------------

import sys     
from PyQt4.QtGui import *      
from PyQt4.QtCore import *     

class MainWindow(QMainWindow):
    #Constructor
    def __init__(self):
        super(MainWindow, self).__init__() #call super class constructor

        button1 = QPushButton("User Settings", self)
        button1.clicked.connect(UserSelection)
        button1.resize(50,50)
        button1.move(350,50)

        self.show()

class UserSelection(?):
    ...

def main():
   app = QApplication(sys.argv) #Create new application
   Main = MainWindow()
   sys.exit(app.exec_()) #Monitor application for events

if __name__ == "__main__":
    main()

我正在编写将某些数据分配给不同季节的代码。我希望程序根据当前月份打印各种数据。

Autumn = 'September'
Autumn = 'October'
Autumn = 'November'
Autumn = 'December'
Autumn = 'January' #(The start Jan 01)
Spring = 'January' #(Jan 02 onwards)
Spring = 'February'
Spring = 'March'
Spring = 'April' #(The start April 04)
Summer = 'Apirl' #(April 05 onwards)
Summer = 'May'
Summer = 'June'
Summer = 'July'

我创建了一个表,并已将数据插入表中.我想知道如何更新/编辑数据.例如,如果表中有多列,其中一列名为'age',列的数据为''17',我现在想用'18'替换'17',我会不会以下？

import sqlite3 as lite
import sys

con = lite.connect('Records.db')

with con:
    cur = con.cursor()    
    cur.execute("INSERT INTO ExampleTable(Age) VALUES(18) WHERE (Age = 17)")

我想知道如何只读取文本文件中每行的第一个字.我尝试了各种代码并尝试更改代码但只能设法从文本文件中读取整行.我使用的代码如下所示:

QuizList = []
with open('Quizzes.txt','r') as f:
            for line in f:
                QuizList.append(line)
        line = QuizList[0]
        for word in line.split():
            print(word)

这是指尝试仅从第一行提取第一个单词.为了重复每一行的过程,我将执行以下操作:

QuizList = []
with open('Quizzes.txt','r') as f:
            for line in f:
                QuizList.append(line)
capacity = len(QuizList)
capacity = capacity-1
index = 0
while index!=capacity:
    line = QuizList[index]
    for word in line.split():
        print(word)
        index = index+1