open file python

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In this short tutorial you will learn how to create a file dialog and load its file contents. The file dialog is needed in many applications that use file access.

Related course:

Create GUI Apps with PyQt5

File Dialog Example
To get a filename (not file data) in PyQT you can use the line:

filename = QFileDialog.getOpenFileName(w, 'Open File', '/')

If you are on Microsoft Windows use

filename = QFileDialog.getOpenFileName(w, 'Open File', 'C:\')

An example below (includes loading file data):

#! /usr/bin/env python
# -*- coding: utf-8 -*-
#
import sys
from PyQt4.QtGui import *

# Create an PyQT4 application object.
a = QApplication(sys.argv)

# The QWidget widget is the base class of all user interface objects in PyQt4.
w = QWidget()

# Set window size.
w.resize(320, 240)

# Set window title
w.setWindowTitle("Hello World!")

# Get filename using QFileDialog
filename = QFileDialog.getOpenFileName(w, 'Open File', '/')
print(filename)

# print file contents
with open(filename, 'r') as f:
    print(f.read())

# Show window
w.show()

sys.exit(a.exec_())

Result (output may vary depending on your operating system):

PyQt File Open Dialog.

Download PyQT Code (Bulk Collection)

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Posted in qt4

2015-04-30

Leave a Reply:

Paul b • Sat, 23 Jan 2016

Thanks for these great tutorials Frank. They are very helpful!

Paul b • Sat, 23 Jan 2016

For windows the line should read:

filename = QFileDialog.getOpenFileName(w, 'Open File', 'C:\\')

You can also just do the following to start in current working directory:

filename = QFileDialog.getOpenFileName(w, 'Open File', '')

Nanodano • Fri, 29 Jan 2016

It's best to choose an option that is cross platform. Another option is to open the file dialog to the users home directory. Here is a cross platform way of doing that with the Python standard library:

from os.path import expanduser
home_dir = expanduser('~')

Melissa • Sat, 26 Mar 2016

Hi there,
I'm somewhat at a loss on labels...how do these work in PYQT4
Thanks
Melissa

Frank • Mon, 28 Mar 2016

To add a label to a window you can call QLabel. I made an example:


import sys
from PyQt4.QtGui import *
# Create an PyQT4 application object.
a = QApplication(sys.argv)
# The QWidget widget is the base class of all user interface objects in PyQt4.
w = QWidget()
# Add label
nameLabel = QLabel("A label in PyQT", w)
nameLabel.move(100, 80)
# Set window size. 
w.resize(320, 240)
# Set window title  
w.setWindowTitle("PyQT Label Example pythonspot.com")
# Show window
w.show()
sys.exit(a.exec_())

Kevin • Sun, 12 Jun 2016

How about load an image file and display it?