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PySimpleGUI

This really is a simple GUI, but also powerfully customizable.

I was frustrated by having to deal with the dos prompt when I had a powerful Windows machine right in front of me. Why is it SO difficult to do even the simplest of input/output to a window in Python??

Python itself doesn't have a simple solution... nor did the many GUI packages I tried. Most tried to do TOO MUCH, making it impossible for users to get started quickly. Others were just plain broken, requiring multiple files or other packages that were missing.

The PySimpleGUI solution is focused on the developer. How can the desired result be achieved in as little and as simple code as possible? This was the mantra used to create PySimpleGUI.

You can add a GUI to your command line with a single line of code. With 3 or 4 lines of code you can add a fully customized GUI.

The customization power comes from the form/dialog box builder that enables users to experience all of the normal GUI widgets without having to write a lot of code.

Features of PySimpleGUI include:
Text
Single Line Input
Buttons including these types:
File Browse
Folder Browse
Non-closing return
Close form
Checkboxes
Radio Buttons
Icons
Multi-line Text Input
Scroll-able Output
Progress Bar
Async/Non-Blocking Windows
Tabbed forms Persistent Windows
Redirect Python Output/Errors to scrolling Window
'Higher level' APIs (e.g. MessageBox, YesNobox, ...)

Getting Started with PySimpleGUI

Installing

pip install PySimpleGUI

or
Simply download the file - PySimpleGUI.py and import it into your code

Prerequisites

Python 3
tkinter

Should run on all Python platforms that have tkinter running on them. Has been thoroughly tested on Windows. While not tested elsewhere, should work on Linux, Mac, Pi, etc.

Using

To us in your code, simply import.... import PySimpleGUI as SG

Then use either "high level" API calls or build your own forms.

SG.MsgBox('This is my first message box')

Yes, it's just that easy to have a window appear on the screen using Python.

APIs

PySimpleGUI can be broken down into 2 types of API's:

High Level single call functions
Custom form functions

Python Language Features

There are a couple of Python language features that PySimpleGUI utilizes heavily that should be understood first...

Variable number of arguments to a function call
Optional parameters to a function call

Variable Number of Arguments

The "High Level" API calls that output values take a variable number of arguments so that they match a "print" statement as much as possible. The idea is to make it simple for the programmer to output as many items as desired and in any format. The user need not convert the variables to be output into the strings. The PySimpleGUI functions do that for the user.

SG.MsgBox('Variable number of parameters example', my_variable, second_variable, "etc")

Each new item begins on a new line in the Message Box

Optional Parameters to a Function Call

This feature of the Python language is utilized heavily as a method of customizing forms and part of forms. Rather than requiring the programmer to specify every possible option for a widget, instead only the options the caller wants to override are specified.

Here is the function definition for the MsgBox function. The details aren't important. What is important is seeing that there is a long list of potential tweaks that a caller can make. However, they don't have to be specified on each and every call.

def MsgBox(*args,
           ButtonColor=None,
           ButtonType=MSG_BOX_OK,
           AutoClose=False,
           AutoCloseDuration=None,
           Icon=DEFAULT_WINDOW_ICON,
           LineWidth=MESSAGE_BOX_LINE_WIDTH,
           Font=None):

If the caller wanted to change the button color to be black on yellow, the call would look something like this:

SG.MsgBox('This box has a custom button color',
          ButtonColor=('black', 'yellow'))

High Level API Calls

The classic "input a value, print result" example. Often command line programs simply take some value as input on the command line, do something with it and then display the results. Moving from the command line to a GUI is very simple. This code prompts user to input a line of text and then displays that text in a messages box:

import PySimpleGUI_local as SG

rc = SG.GetTextBox('Title', 'Please input something')
SG.MsgBox('Results', 'The value returned from GetTextBox', rc)

Message Boxes

In addition to MsgBox, you'll find a several API calls that are shortcuts to common messages boxes. You can achieve similar results by calling MsgBox with the correct parameters.

The differences tend to be the number and types of buttons. Here are the calls and the windows that are created.

import PySimpleGUI as SG

SG.MsgBoxOK('This is an OK MsgBox')

SG.MsgBoxOKCancel('This is an OK Cancel MsgBox')

SG.MsgBoxCancel('This is a Cancel MsgBox')

SG.MsgBoxYesNo('This is a Yes No MsgBox')

SG.MsgBoxError('This is an error MsgBox')

SG.MsgBoxAutoClose('This is an autoclose MsgBox')

SG.ScrolledTextBox(my_text, Height=10)

Take a moment to look at that last one. It's such a simple API call and yet the result is awesome. Rather than seeing text scrolling past on your display, you can capture that text and present it in a scrolled interface.

High Level User Input

There are 3 very basic user input high-level function calls. It's expected that for most applications, a custom input form will be created.

GetTextBox
GetFileBox
GetFolderBox

submit_clicked, value = SG.GetTextBox('Title', 'Please enter anything')

submit_clicked, value = SG.GetFileBox('Title', 'Choose a file')

submit_clicked, value = SG.GetPathBox('Title', 'Choose a folder')

Custom Form API Calls

This is the FUN part of the programming of this GUI. In order to really get the most out of the API, you should be using an IDE that supports auto complete or will show you the definition of the function. This will make customizing go smoother.

It's both not enjoyable nor helpful to immediately jump into tweaking each and every little thing available to you. Let's start with a basic Browse for a file and do something with it.

COPY THIS DESIGN PATTERN!

with SG.FlexForm('SHA-1 & 256 Hash', AutoSizeText=True) as form:
    form_rows = [[SG.Text('SHA-1 and SHA-256 Hashes for the file')],
                 [SG.InputText(), SG.FileBrowse()],
                 [SG.Submit(), SG.Cancel()]]
    (button, (source_filename, )) = form.LayoutAndShow(form_rows)

This context manager contains all of the code needed to specify, show and retrieve results for this form:

It's important to use the "with" context manager. PySimpleGUI uses tkinter. tkinter is very picky about who releases objects and when. The with takes care of disposing of everything properly for you.

You will use this design pattern or code template for all of your "normal" (blocking) types of input forms.

PySimpleGUI's goal with the API is to be easy on the programmer. An attempt was made to make the program's code visually match the window on the screen. The way this is done is that a GUI is broken up into "Rows". Then each row is broke up into "Elements" or "Widgets". Each element is specified by names such as Text, Button, Checkbox, etc.

Some elements are shortcuts, again meant to make it easy on the programmer. Rather than writing a Button, with name = "Submit", etc, the caller simply writes Submit.

Going through each line of code

with SG.FlexForm('SHA-1 & 256 Hash', AutoSizeText=True) as form:

This creates a new form, storing it in the variable form.

    form_rows = [[SG.Text('SHA-1 and SHA-256 Hashes for the file')],

The next few rows of code lay out the rows of elements in the window to be displayed. The variable form_rows holds our entire GUI window. The first row of this form has a Text element. These simply display text on the form.

                 [SG.InputText(), SG.FileBrowse()],

Now we're on the second row of the form. On this row there are 2 elements. The first is an Input field. It's a place the user can enter strings. The second element is a File Browse Button. A file or folder browse button will always fill in the text field to it's left unless otherwise specified. In this example, the File Browse Button will interact with the InputText field to its left.

			    [SG.Submit(), SG.Cancel()]]

The last line of the form_rows variable assignment contains a Submit and a Cancel Button. These are buttons that will cause a form to return its valueso the caller.

    (button, (source_filename, )) = form.LayoutAndShow(form_rows)

This is the code that displays the form, collects the information and returns the data collected. In this example we have a button return code and only 1 input field.

Return values

Return information from FlexForm, SG's primary form builder interface, is in this format:

(button, (value1, value2, ...))

Don't forget all those ()'s of your values won't be coreectly assigned.

If you have a SINGLE value being returned, it is written this way:

(button, (value1,))

Forgetting the comma will mess you up but good

All Widgets / Elements

This code utilizes as many of the elements in one form as possible.

with FlexForm('Everything bagel', AutoSizeText=True, DefaultElementSize=(30,1)) as form:
    layout = [[Text('Here they all are!', Size=(30,1), Font=("Helvetica", 25), TextColor='red')],
              [Text('Here is some text with font sizing', Font=("Helvetica", 15))],
              [InputText()],
              [Checkbox('My first checkbox!'), Checkbox('My second checkbox!', Default=True)],
              [Radio('My first Radio!', "RADIO1", Default=True), Radio('My second checkbox!', "RADIO1")],
              [Multiline(DefaultText='This is the DEFAULT text should you decide not to type anything', Scale=(2, 10))],
              [InputCombo(['choice 1', 'choice 2'], Size=(20, 3))],
              [Text('_'  * 90, Size=(60, 1))],
              [Text('Choose Source and Destination Folders', Size=(35,1))],
              [Text('Source Folder', Size=(15, 1), AutoSizeText=False), InputText('Source'), FolderBrowse()],
              [Text('Destination Folder', Size=(15, 1), AutoSizeText=False), InputText('Dest'), FolderBrowse()],
              [SimpleButton('Your Button with any text you want')],
              [SimpleButton('Big Text', Size=(12,1), Font=("Helvetica", 20))],
              [Submit(), Cancel()]]

    (button, (values)) = form.LayoutAndShow(layout)




    MsgBox('Results', 'You clicked {}'.format(button),'The values returned from form', values , Font = ("Helvetica", 15))

This is a somewhat complex form with quite a bit of custom sizing to make things line up well. This is code you only have to write once. When looking at the code, remember that what you're seeing is a list of lists. Each row contains a list of Graphical Elements that are used to create the form.

Clicking Submit caused the form call to return and the call to MsgBox is made to display the results.

Built With

Contributing

A MikeTheWatchGuy production... entirely responsible for this code

Versioning

1.0.9 - July 10, 2018 - Initial Release

Authors

License

This project is licensed under the MIT License - see the LICENSE.md file for details

Acknowledgments

Jorj McKie was the motivator behind the entire project. His wxsimpleGUI concepts sparked PySimpleGUI into existence

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