- Registron as a python program
- GUI Basics
- Program utils module
- Using Qt designer with pyrcc and pyuic
- The program logic
- Creating the windows exe with pyinstaller
- References
>>>print("Hello World!")
As shown in the examples, the python 3 requires the print function to have its argument in braces like any other function where python 2 allows more flexibility. This ease of use allowed this project to be implemented speedily.
Computers have operated in CLI (Command Line Interface) from its early days of use till date. However, in the ancient days of computing, they only had the CLI to work with. This is just the console where we type a bunch of digital text to execute program instructions. After Xerox found GUI (Graphical User Interface), Apple and Microsoft took the idea and implemented it in their ways. Ever since, GUI has been known to be the most user friendly environment to work with on computers. Registron could have been built as a CLI program but then it will serve less of its purpose as students who are less enlightened about computers will find it difficult to use. There are 4 modules that can be used to build GUI programs in python and they are: - Tkinter - wxPython - PyGTK - PyQt PyQt was chosen for development because: - It is stable for cross-platform GUI development - It has a Qt designer which is WYSIWYG editor to draw the GUI before importing to the code to work with - The development machine (noxiux) has a KDE desktop and Qt applications run really fine on KDE as GTK works on Gnome. Before getting started with the actual GUI development of registron, we put to consideration some simple python functions that will be required in the program. These are the core functions and they will work just fine even in a CLI environment. Python as a speech based program needs to talk so we create a simple talking function for it. For this implementation, [pyttsx][1] was used to interpret text to speech. As voices were programmatically written as text, the pyttsx function translates it to a voice. We have a function that hashes passwords to MD5 (Message digest algorithm) and also checks for admin password authentication in comparison with the stored hashed password. The information storage system for registron is a JSON file rather than a database. Even as sqlite had been thought of on initial development, the information to be stored on registron does not seem much of enough for a relational database and this led to a change of thoughts to make use of the JSON file instead. If there is a future need for a larger data storage then the program can be re-adjusted to work with a sqlite or mysql database. SQL Alchemy may also be thought of for use. With the use of the JSON file, our program has to write data to the file and it does so by opening the JSON file and converting it to a dictionary object to append and modify data in it. To achieve this, we create a dict_object function to handle the operation. Finally, a simple function that opens the users web browser to show the online documentation. The GUI basics section reveals that one of the major reasons why PyQt is the GUI module option for registron is its WYSIWYG Qt designer. Qt designer allows the development to be with ease as they are buttons, labels and display items that can be dragged to a window frame to determine how the program should look. After this whole simple design process, a .ui file is generated in XML format. To convert this XML data to a python program, we leverlage the pyuic installation we have. This is a python UI compiler and its goal is to translate our XML ui to a python module. This module should be imported into our actual program as we can't make direct changes to it since it may change each time we make GUI updates and compile into python. Pyuic is used as shown:pyuic designfile.ui -o design.py
That may be considered all that is required for the program from Qt designer but in cases like registron where we have some images added with resource files that are listed in a app.qrc file, we have to convert this resource files into binary to work properly with the program. For this we use pyrcc which is python resource compiler.
pyrcc app.qrc > app_rc.py
That generates a app_rc.py python module for use with our GUI module. For images that vary in the GUI we use QPixmap to dynamically add images to the canvas so it needs to prior compilation of binary as it just fetches the image from its source.
Registron has a very simple I/O logic which will be summarized in a pseudo code and a flow chart. >start programif student: enter matric; else if administrator: goto 2;
if matric number exists: grant access: else: display unauthorized user warning;
if access granted: check wanted courses and click update
while 2:
if admin username and password is correct: grant access; else: display error;
admin modifies program and school preferences
end while;
stop program
Now we install UPX for compressing the exe file and we navigate to our Pyinstaller directory to run the following
python makespec.py --onefile --upx registron.py
python build.py registron.spec
Now this creates our registron.exe file and it takes a longer build time because upx takes extra time compressing the executable.
Some useful references: - [http://pyttsx.readthedocs.org/en/latest/][0] - [https://github.com/parente/pyttsx][1] - [http://upx.sourceforge.net/#download][2] - [http://josephrex.me/getting-started-with-gui-development-in-python/][3] - [http://pyqt.sourceforge.net/Docs/PyQt4/classes.html][4] - [http://pyqt.sourceforge.net/Docs/PyQt4/designer.html][5] - [https://wiki.python.org/moin/PyQt4][6] - [http://doc.qt.digia.com/4.6/index.html][7] - [http://www.riverbankcomputing.com/software/sip/intro][8] - [http://pythonkit.com/PyQt-pdf.html][9] - [http://zetcode.com/gui/pyqt4/][10] - [http://pyqt.sourceforge.net/Docs/PyQt4/designer.html][11] - [http://pyinstaller.org/][12] - [https://www.google.ca/#q=text+to+speech+implementation][13]