Python UI design

Notes collected from: Learn How to Quickly Create UIs in Python.

Image

Photo by Eftakher Alam on Unsplash

Motivation

Sometimes, however, your target audience is not technical enough.
They’d love to use your python scripts but only as long as they didn’t have to look at a single line of code.
They need a Uer Interface (UI) in such a case.
* years ago, I used to code UIs using Java/Python/Matlab. They are good, but time-consuming in some cases. Some environments also provide graphical operations for UI design, which is essentially UI for UI designers :)

The task: UI to check if two files are identical

Design a UI to check if two files are identical, without mannually referecing to the Python scripts.
* for file compare algorithms, pls check a previous post: Beyond Compare
We essentially need a way to load up two files, and then choose the encryption we would like to use to do the file comparison.

Python Libraries Available for UI usage

There are essentially 3 big Python UI libraries; Tkinter, wxPython and PyQT.

Code the UI

To build that UI, we can use the following code:

import PySimpleGUI as sg
layout = [
    [sg.Text('File 1'), sg.InputText(), sg.FileBrowse(),
     sg.Checkbox('MD5'), sg.Checkbox('SHA1')
     ],
    [sg.Text('File 2'), sg.InputText(), sg.FileBrowse(),
     sg.Checkbox('SHA256')
     ],
    [sg.Output(size=(88, 20))],
    [sg.Submit(), sg.Cancel()]
]
window = sg.Window('File Compare', layout)
while True:                             # The Event Loop
    event, values = window.read()
    # print(event, values) #debug
    if event in (None, 'Exit', 'Cancel'):
        break

which results in: Image

Plugging in the logic

We simply need to monitor for what the user inputs and then act accordingly.

import PySimpleGUI as sg
import re
import hashlib
def hash(fname, algo):
    if algo == 'MD5':
        hash = hashlib.md5()
    elif algo == 'SHA1':
        hash = hashlib.sha1()
    elif algo == 'SHA256':
        hash = hashlib.sha256()
    with open(fname) as handle: #opening the file one line at a time for memory considerations
        for line in handle:
            hash.update(line.encode(encoding = 'utf-8'))
    return(hash.hexdigest())
layout = [
    [sg.Text('File 1'), sg.InputText(), sg.FileBrowse(),
     sg.Checkbox('MD5'), sg.Checkbox('SHA1')
     ],
    [sg.Text('File 2'), sg.InputText(), sg.FileBrowse(),
     sg.Checkbox('SHA256')
     ],
    [sg.Output(size=(88, 20))],
    [sg.Submit(), sg.Cancel()]
]
window = sg.Window('File Compare', layout)
while True:                             # The Event Loop
    event, values = window.read()
    # print(event, values) #debug
    if event in (None, 'Exit', 'Cancel'):
        break
    if event == 'Submit':
        file1 = file2 = isitago = None
        # print(values[0],values[3])
        if values[0] and values[3]:
            file1 = re.findall('.+:\/.+\.+.', values[0])
            file2 = re.findall('.+:\/.+\.+.', values[3])
            isitago = 1
            if not file1 and file1 is not None:
                print('Error: File 1 path not valid.')
                isitago = 0
            elif not file2 and file2 is not None:
                print('Error: File 2 path not valid.')
                isitago = 0
            elif values[1] is not True and values[2] is not True and values[4] is not True:
                print('Error: Choose at least one type of Encryption Algorithm')
            elif isitago == 1:
                print('Info: Filepaths correctly defined.')
                algos = [] #algos to compare
                if values[1] == True: algos.append('MD5')
                if values[2] == True: algos.append('SHA1')
                if values[4] == True: algos.append('SHA256')
                filepaths = [] #files
                filepaths.append(values[0])
                filepaths.append(values[3])
                print('Info: File Comparison using:', algos)
                for algo in algos:
                    print(algo, ':')
                    print(filepaths[0], ':', hash(filepaths[0], algo))
                    print(filepaths[1], ':', hash(filepaths[1], algo))
                    if hash(filepaths[0],algo) == hash(filepaths[1],algo):
                        print('Files match for ', algo)
                    else:
                        print('Files do NOT match for ', algo)
        else:
            print('Please choose 2 files.')
window.close()

Running the above code will give you the following outcome:
Image

Remarks

  • this library allows you to quickly spin up simple python UIs and share them
  • You will still have the problem of having to run the code to get the UI
  • but you can consider using something like PyInstaller which will turn your python script into a .exe that people can simply double click.