<< Chapter < Page Chapter >> Page >

Figure 2 shows the output produced by running this program.

Figure 2 . Output from Feet to Meters converter program.

Output from Feet to Meters convertor program.

Will discuss in fragments

As is my custom, I will break the program down and discuss it in fragments. I will attempt to explain why the various parts of the programbehave as they do. The first fragment is shown in Listing 1 .

The root

Listing 1 shows a skeleton of the program with most of the code removed to expose the root and the main loop .

Listing 1 . The root.
from tkinter import * root = Tk()root.title("Feet to Meters") root.mainloop()

Figure 3 shows the output produced by running the skeleton code in Listing 1 .

Figure 3 . Output from Listing 1.

Image showing output of code for root only.

According to Hello, Tkinter ,

"To initialize Tkinter, we have to create a Tk root widget. This is an ordinary window, with a title bar and other decoration provided by your window manager. You should only create one root widget for each program, and it must be created before any other widgets."

(Note that according to TkDocs , the name of the module was changed from Tkinter to tkinter with the release of Python 3.0.)

The empty window that you see in Figure 3 behaves like a standard Windows window on my machine. The three buttons in the upper-right corner behave asexpected while the menu icon in the upper-left corner behaves as expected. (The icon in the upper-left corner appears to be the TCL feather logo.)

Import statements

TkDocs has this to say about the two import statements at the top of Listing 9 ,

"These two lines tell Python that our program needs two modules. The first, "tkinter", is the standard binding to Tk, which when loaded also causes the existing Tk library on your system to be loaded. The second, "ttk", is Python's binding to the newer "themed widgets" that were added to Tk in 8.5."

That document goes on to provide a very interesting TIP regarding the use of the asterisk (*) with the first import statement and the non-use of the asteriskwith the second import statement. I will leave it as an exercise for the student to examine that material.

The calculate function

I'm going to skip over the calculate function (see Listing 9 ) at this point and return to discuss it in context later.

Add a Frame widget

The first statement in Listing 2 creates a Frame widget and places it in the root .

Listing 2 . Add a Frame widget.
mainframe = ttk.Frame(root, padding="3 3 12 12") mainframe.grid(column=0, row=0, sticky=(N, W, E, S))mainframe.columnconfigure(0, weight=1) mainframe.rowconfigure(0, weight=1)

According to TkDocs ,

"Next, we create a frame widget, which will hold all the content of our user interface, and place that in our main window. The "columnconfigure"/"rowconfigure" bits just tell Tk that if the main window is resized, the frame should expand to take up the extra space."

According to Tkinter 8.5 reference: a GUI for Python ,

"Like the Tkinter Frame widget, the ttk.Frame widget is a rectangular container for other widgets."

That document goes on to explain that the first argument to Frame is the parent of the Frame . In this case, the frame will be a child of root . After that, you can enter any of about nine different options, one of which is padding .

Questions & Answers

I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
How can I make nanorobot?
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Itse 1359 introduction to scripting languages: python. OpenStax CNX. Jan 22, 2016 Download for free at https://legacy.cnx.org/content/col11713/1.32
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Itse 1359 introduction to scripting languages: python' conversation and receive update notifications?