PyQt6 write text from QLineEdit into a file doesn't work

Question

I wanted to get the text of QLineEdit (generated with designer) and write it into a file (lines 143-149), but when I print the string, it works. Only when I try to write it to the file, it probably returns an empty string and I got no errors.

import PySide6
from PySide6.QtWidgets import QApplication, QMainWindow, QMessageBox
from PySide6 import QtSql
import time
from frm_main import Ui_root
from entpwd1 import Ui_Form
from newpwd_1 import Ui_Form as Ui_Form_2
from pwewdgt2 import Ui_pweingabe_wdgt_2
from genpwd_1 import Ui_Form as Ui_Form_3
from chkpwd_1 import Ui_Form as Ui_Form_4
from chpw import Ui_Form as Ui_Form_5
from pw_incorrect import Ui_Warnung
from show_pw_frm import Ui_Form as Ui_Form_1_2
import subprocess
from pwdsshow import Ui_wind
import hashlib
import secrets
import string
import os
#import threading

#------------------------------------------------------------------------------------------------
class frm_pwds():
    def __init__(self):
        super().__init__()
        print("test2")
         
        print("test3")
        
    def anzeigen(self):
        datei1=open("Passwords.txt", "r")
        datei=datei1.read()
        print(datei)
        
        os.popen("anz.py")
        time.sleep(2)
        
        
        
       
        print(123456789)
        fle=open("Zwischendatei.txt", "r")
        file2 = "aescrypt.exe -e -p " + fle.read() + " Passwords.txt"
        subprocess.getoutput(file2)
        print(12345678910)
        fle.close()
        datei1.close()
        time.sleep(5)
        os.remove("Passwords.txt")
        open("Zwischendatei.txt", "w").write("")
        
            
        

class frm_entpwd(QMainWindow, Ui_Form):
    global datei
    def __init__(self):
        super().__init__()
        self.setupUi(self)
        self.bst.clicked.connect(self.clckd)
        global datei
    def clckd(self):
        entrytext=self.lineEdit.text()
        hex_hash=hashlib.sha256(entrytext.encode())
        hash=hex_hash.hexdigest()
        hex_hash=hashlib.sha256(hash.encode())
        hash=hex_hash.hexdigest()
        file=open("GKEY.txt", "r")
        content=file.read()
        if (hash==content):
            self.close()
            file="aescrypt.exe -d -p "+ entrytext + " Passwords.txt.aes"
            subprocess.getoutput(file)
            global datei
            fl=open("Passwords.txt", "r")
            os.popen("anz.py")
            datei = fl.read() #subprocess.getoutput("showpwd.bat")
            fl.close()
            open("Zwischendatei.txt", "w").write(entrytext)
            
            
            
            print("test")
        else:
            wrng.show()
        self.lineEdit.clear()
            
class frm_warning(QMainWindow, Ui_Warnung):
    def __init__(self):
        super().__init__()
        self.setupUi(self) 
        self.buttonBox.clicked.connect(self.close) 


#------------------------------------------------------------------------------------------------
#------------------------------------------------------------------------------------------------
#------------------------------------------------------------------------------------------------

lg=""
pw=""
us=""
class frm_addpwd(QMainWindow, Ui_Form_2):
    def __init__(self):
        super().__init__()
        self.setupUi(self)
        self.bt_abort.clicked.connect(self.close)
        self.bt_ok.clicked.connect(self.key_entering)
    def key_entering(self):

        entry_login_text=self.entry_login.text()
        entry_pw_text=self.entry_pw.text()
        entry_using_text=self.entry_using.text()
        lg='Benutzername: ' + entry_login_text
        pw='Passwort: ' + entry_pw_text
        us='Verwendung: ' + entry_using_text
        print(lg)
        
        eingabefeld.show()
class frm_addpwd2(QMainWindow, Ui_pweingabe_wdgt_2):
    def __init__(self):
        super().__init__()
        self.setupUi(self)
        self.bt_ok_2.clicked.connect(self.add)
    def add(self):
        plntext=self.entry_pw_2.text()
        hshtxt=hashlib.sha256(plntext.encode())
        hshtxt=hshtxt.hexdigest()
        hshtxt=hashlib.sha256(hshtxt.encode())
        hshtxt=hshtxt.hexdigest()
        print(hshtxt)

        file=open("GKEY.txt", "r")
        content=file.read()
        if (hshtxt==content):
            self.close()
            file="aescrypt.exe -d -p "+ plntext + " Passwords.txt.aes"
            subprocess.getoutput(file)
            time.sleep(2)
            fl=open("Passwords.txt", "a")
            
            #-------Error--------
            print(lg)
            fl.write(lg)
            fl.write("\n")
            fl.write(pw)
            fl.write("\n")
            fl.write(us)
            fl.write("\n\n")
            
            #datei = fl.write() #subprocess.getoutput("showpwd.bat")
            fl.close()
            open("Zwischendatei.txt", "w").write("") 
            file2 = "aescrypt.exe -e -p " + plntext + " Passwords.txt"
            
            subprocess.getoutput(file2)
            time.sleep(5)
            os.remove("Passwords.txt")
            open("Zwischendatei.txt", "w").write("")
            
            
            print("test")
        else:
            wrng.show()
        self.entry_pw_2.clear()
#------------------------------------------------------------------------------------------------
#------------------------------------------------------------------------------------------------
#------------------------------------------------------------------------------------------------
class frm_genpwd(QMainWindow, Ui_Form_3):
    def __init__(self):
        super().__init__()
        self.setupUi(self)
        self.generate.clicked.connect(self.gnr)
    def gnr(self):
        letters = string.ascii_letters
        digits = string.digits
        special_chars = string.punctuation

        alphabet = letters + digits + special_chars

        # fix password length
        pwd_length = 12

        # generate a password string
        pwd = ''
        for i in range(pwd_length):
            pwd += ''.join(secrets.choice(alphabet))

        print(pwd)

        # generate password meeting constraints
        while True:
            pwd = ''
            for i in range(pwd_length):
                pwd += ''.join(secrets.choice(alphabet))

            if (any(char in special_chars for char in pwd) and 
                sum(char in digits for char in pwd)>=2):
                    break
            print(pwd)
            self.pw_generated.setText(pwd)
#------------------------------------------------------------------------------------------------
class frm_chkpwd(QMainWindow, Ui_Form_4):
    def __init__(self):
        super().__init__()
        self.setupUi(self)
        self.check.clicked.connect(self.cnedt_chk)
    def cnedt_chk(self):
        cnter=0
        inh=self.entpw.text()
        str = inh 
        print(list(str))
        for a in (list(str)):
            print(a)
            if (a.isupper):
                cnter=cnter+1
                print("upper")
            if (a.isdigit):
                cnter=cnter+1
                print("dig")
            if (a.islower):
                cnter=cnter+1
                print("lower")
            if (a.isascii):
                cnter=cnter+1
                print("ascii")
        self.sec_step.setText(str(cnter))
#------------------------------------------------------------------------------------------------
class frm_chgkey(QMainWindow, Ui_Form_5):
    def __init__(self):
        super().__init__()
        self.setupUi(self)
        
#------------------------------------------------------------------------------------------------
class frm_entpwd_2(QMainWindow, Ui_Form_5):
    def __init__(self):
        super().__init__()
        self.setupUi(self)
#------------------------------------------------------------------------------------------------
#------------------------------------------------------------------------------------------------
class Root(QMainWindow, Ui_root, Ui_Form):
    def __init__(self):
        super().__init__()
        self.setupUi(self)
        self.pushButton.clicked.connect(self.ntp)
        self.pushButton_2.clicked.connect(self.adp)
        self.pushButton_3.clicked.connect(self.gnp)
        self.pushButton_4.clicked.connect(self.ckp)
        self.pushButton_5.clicked.connect(self.chp)
        
    def ntp(self):
        frm_ntpw.show()

    def adp(self):
        frm_adpw.show()
    def gnp(self):
        frm_gnp.show()
    def ckp(self):
        frm_ckp.show()
    def chp(self):
        frm_chpw.show()
    
        

        

app=QApplication()
root=Root()
root.show()
#----------------Frames für direkte Unterwigets der QMainWindow-Klasse------------------
frm_ntpw=frm_entpwd()
frm_adpw=frm_addpwd()
frm_gnp=frm_genpwd()
frm_ckp=frm_chkpwd()
frm_chpw=frm_chgkey()
#----------------Ende Frames------------------------------------------------------------
wrng=frm_warning() 
showpasswords=frm_pwds()
#-----------------Klasse entpwd--------------------------------------
eingabefeld=frm_addpwd2()
app.exec()
    
        

I expected that the text would appear in the text file, but the text is the same like before.

Thanks in advance