Python crashing when trying to view data in PyQT5

Question

Apologies if my title is unclear; I'm trying to retrieve some data from an SQLLite database (which is working) and show it to the user on a window in PyQt5. So far, I've managed to retrieve the result and print in Python, but when trying to add/view the results in the window Python simply crashes. I've inserted the code which isn't working below. (The indentation has gone slightly funny when copying it, but it is perfectly fine in my file).

class Profile(QWidget):
def __init__(self, Type):
    super().__init__()
    self.window = QWidget()
    self.window.setGeometry(100,100, 350, 400)
    self.window.setWindowTitle("Welcome")
    self.window.show()
    self.Choices()

def Choices(self):
    self.layout = QGridLayout()
    c.execute('''SELECT username, teamname FROM Users WHERE username = ?''',
    (user,))
    result = c.fetchone()
    print(result)
    print(user)

    self.TeamInfo = QLabel(result)
    self.layout.addWidget(self.TeamInfo)
    self.window.setLayout(self.layout)
    self.window.show()

user is a global variable in a previous window (the log in page) to avoid the user having to reenter their username. This section is not included, as that is not the problem. All the other buttons in the class are working - it is just this particular section. Any help as to how to solve this is greatly appreciated, I figure the problem is the line self.TeamInfo = QLabel(result) but I don't have the PyQT5 knowledge on how to solve this.

Edit: I have included a screenshot of the error message I'm getting.

what is the output of `print(result, type(result))`? and show the complete error message. — eyllanesc, Apr 25 '19 at 18:52
@eyllanesc the output is: ('john1', 'johns team') , and the error message is a different window saying Python has stopped working — NotEvenTheRain, Apr 26 '19 at 12:29

Tibor Szűcs · Answer 1 · 2019-04-25T13:56:33.713

1

If I understand right you are trying to add a text to QLabel, right? According to the documentation adding text to it is done by: QLabel().setText(result).

Edit: Could you please try this and tell me what the compiler is complaining about?

label = QLabel()
label.setText(result)
self.layout.addWidget(label)

edited Apr 25 '19 at 13:56

answered Apr 25 '19 at 11:42

Tibor Szűcs

66
5

Could you please paste what is the compiler saying when running the code? – Tibor Szűcs Apr 25 '19 at 13:59
The compiler brings up a window complaining that Python has stopped working, tries to fix it then brings up the window that Python has stopped working entirely, it's printing `user` so it's able to get past that point. – NotEvenTheRain Apr 26 '19 at 11:25
I tried your code and it seems resolved by eyllanesc's reply. It was the problem that you were trying to put a tuple inside the Label, which seems like it only accepts string. I get this error in my IDE when I try to put tuple inside the label: `QLabel(parent: QWidget = None, flags: Union[Qt.WindowFlags, Qt.WindowType] = Qt.WindowFlags()): argument 1 has unexpected type 'tuple'` – Tibor Szűcs Apr 27 '19 at 13:32

S. Nick · Answer 2 · 2019-04-26T14:19:37.963

Try it:

import sys
from PyQt5.QtCore import *
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *

import sqlite3

class Profile(QWidget):
    def __init__(self, Type=None):
        super().__init__()
        self.window = QWidget()
        self.window.setGeometry(100,100, 350, 400)
        self.window.setWindowTitle("Welcome")
        self.Choices()

    def Choices(self):
        self.layout = QGridLayout()

#        c.execute('''SELECT username, teamname FROM Users WHERE username = ?''',
#                  (user,))
#        result = c.fetchone()
#

        user = "Nick" 
        try:
            self.conn = sqlite3.connect("database.db")
            self.c = self.conn.cursor()
#            result = self.c.execute("SELECT * from students WHERE name='{}'".format(user) )   
            result = self.c.execute("SELECT * from students WHERE name=?", (user, ))

            row = result.fetchone()                                               # <---
            print("\nrow->", type(row), row)
            serachresult = "Rollno : "+str(row[0])+'\n'+"Name : "+str(row[1])+'\n'+"Branch : "+str(row[2])+'\n'+"Sem : "+str(row[3])+'\n'+"Address : "+str(row[4])
            QMessageBox.information(QMessageBox(), 'Successful', serachresult)
            self.conn.commit()
            self.c.close()
            self.conn.close()
        except Exception:
            QMessageBox.warning(QMessageBox(), 'Error', 'Could not Find student from the database.')

        print(result)
        print(user)

        self.TeamInfo = QLabel(", ".join([ str(i) for i in row ]))                # <---
        self.layout.addWidget(self.TeamInfo)
        self.window.setLayout(self.layout)
        self.window.show()

if __name__ == '__main__':
     app = QApplication(sys.argv)
     main = Profile()
     main.show()
     sys.exit(app.exec_())

`self.c.execute("SELECT * from students WHERE name='{}'".format(user))` == SQL Injection :-( .... read https://docs.python.org/3/library/sqlite3.html: `# Never do this -- insecure! symbol = 'RHAT' c.execute("SELECT * FROM stocks WHERE symbol = '%s'" % symbol)`. Better to use a placeholder: `self.c.execute("SELECT * from students WHERE name=?", (user, ))` — eyllanesc, Apr 26 '19 at 14:11
Do not provide code just to respond to the OP, here the most important thing is that the question is that it is of quality so that it serves the whole community, and always use: *Try it* does not help, why do not you explain the code failure of the OP and your solution? — eyllanesc, Apr 26 '19 at 14:23

Python crashing when trying to view data in PyQT5

2 Answers2