argument 1 has unexpected type ‘Ui_mainWindow’

I’m trying to make a GUI for a small program I wrote with the help of some people from here, anyway, I made the GUI in PyQt and it looks fine. I added a button called dirButton that says “Choose Directory”

self.dirButton = QtGui.QPushButton(self.buttonWidget)
self.dirButton.setGeometry(QtCore.QRect(0, 0, 91, 61))
self.dirButton.setObjectName(_fromUtf8("dirButton"))
self.dirButton.clicked.connect(self.browse)

and in the bottom line there I’ve made it call self.browse when I click it, which is:

def browse(self):
    filename = QtGui.QFileDialog.getOpenFileName(self, 'Open File', '.')
    fname = open(filename)
    data = fname.read()
    self.textEdit.setText(data)
    fname.close()

However, this is the error I get:

Traceback (most recent call last):
File "C:UsersKevinDesktoppython-tumblr-0.1antearaGUI.py", line 88, in browse
filename = QtGui.QFileDialog.getOpenFileName(self, 'Open File', '.')
TypeError: QFileDialog.getOpenFileName(QWidget parent=None, QString caption=QString(),     QString directory=QString(), QString filter=QString(), QString selectedFilter=None, QFileDialog.Options options=0): argument 1 has unexpected type 'Ui_mainWindow'

So, ui_mainWindow is the class that all of my GUI buttons and the GUI itself is stored in.

class Ui_mainWindow(object):

I don’t understand why I’m getting an error, does anyone have any ideas?

Here is a pastebin link to the entire GUI: http://pastebin.com/BWCcXxUW

Answers:

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Method 1

As I understand, you are using Ui_mainWindow generated from .ui file. As you can see Ui_mainWindow is just python class which contains widgets. getOpenFileName recieves QWidget instance as first parameter. So you need to subclass QWidget or QMainWindow and define methods in that class.

Code will look like this:

import sys

from PyQt4 import QtCore, QtGui

from file_with_ui import Ui_MainWindow

class Main(QtGui.QMainWindow, Ui_MainWindow):
    def __init__(self):
        QtGui.QMainWindow.__init__(self)
        self.setupUi(self)

    def browse(self):
        filename = QtGui.QFileDialog.getOpenFileName(self, 'Open File', '.')
        fname = open(filename)
        data = fname.read()
        self.textEdit.setText(data)
        fname.close()

if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)
    window = Main()
    window.show()
    sys.exit(app.exec_())

Alternatively you can store ui as instance attribute:

class Main(QtGui.QMainWindow):
    def __init__(self):
         QtGui.QMainWindow.__init__(self)
         self.ui=Ui_MainWindow()
         self.ui.setupUi(self)

And acces your controls through self.ui, e.g.: self.ui.textEdit.setText(data)

Consider reading tutorial about pyuic usage PyQt by Example (Session 1)

Method 2

import the following:

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

In class Ui_MainWindow(object), replace object with QWidget:

Ui_MainWindow(QWidget)

Method 3

def browseFiles(self):
        text, placeholder = QFileDialog.getOpenFileName(None, 'Select file')

The way it worked out for me is to use None, rather than self, as self inherits the type of the window above it, which is expected to be None, but is given QMainWindow as a type.

I also unpacked the tuple it returns, since this function returns two objects to work with.

I hope this helps, perhaps someone else could explain this better, as to why it works.

TLDR: The function expects None as the first parameter, but inherits a QmainWindow as type, due to self.

Method 4

file = str(QFileDialog.getExistingDirectory(None, “Select Directory”))

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0