December 8<sup>th</sup>, 2020

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<center><h2>Efforts to Learn</h2></center>
I have been slowly trying to learn to program using my Raspberry-Pi. I've learned a little bit about guizero, I can make a "Wanted Poster" and almost actually understand how I did it and why it worked. (see <a href="https://peakd.com/hive-163521/@bashadow/raspberry-pi-update-a-week-and-a-couple-of-days">Last post</a>)

Through it I learned how to change colors and fonts and font size and how to import pictures.

Now I am trying to learn how to make something functional. One of the Links that @mytechtrail provided me was to Real Python Tutorial <a href="https://realpython.com/python-gui-tkinter/">Python GUI Programming With Tkinter</a>. Contained in that was a temperature conversion example:

![real python temp coversion program](https://files.peakd.com/file/peakd-hive/bashadow/dyiZSKCA-real20python20temp20coversion20image.png)

I played around with it quite a bit the last couple of days and this is my incomplete version with a few modifications that I learned:

![my temp coversion so far.png](https://files.peakd.com/file/peakd-hive/bashadow/hPdoEEbn-my20temp20coversion20so20far.png)

*Real Python* version is a fixed size window, that when you type a number in the Celsius symbol will shift and a label will hold the conversion when you click the arrow button.

One of the first things I modified was making the window re- sizable along the horizontal, `window.resizable(width=True, height=False)` (which in the finished version I will likely go back to false for resize option). I also played with the background colors as practice. It did take me some research to find out how to change the main window background color.
 
Where `bg="color"` worked for the button and the label, it did not work for setting the window color, however I did find `.configure(bg="salmon")` command that let me change the color. I still do not understand why `bg="color"` would not work so a comment if you can explain would be appreciated. Is it a global seting verse a local setting thing?

Now about the **Reset** button. I want that to clear the input box and to give it the focus when the button is pushed. 
```
btn_clear = tk.Button(text="Reset")
#ent_temperature.entry.delete(0, tk.end)
```
That is what I have for now, it does not clear the input box.

Below is my modified code, followed by the Real python code example.

<hr>

```

import tkinter as tk

#gui.configure(bg='blue')


def fahrenheit_to_celsius():
    """Convert the value for Fahrenheit to Celsius and insert the
    result into lbl_result.
    """
    fahrenheit = ent_temperature.get()
    celsius = (5/9) * (float(fahrenheit) - 32)
    lbl_result["text"] = f"{round(celsius, 2)} \N{DEGREE CELSIUS}"

# Set-up the window
window = tk.Tk()
window.title("Temperature Converter")
window.resizable(width=True, height=False)
window.configure(bg="salmon")
# Create the Fahrenheit entry frame with an Entry
# widget and label in it
frm_entry = tk.Frame(master=window)
ent_temperature = tk.Entry(master=frm_entry, width=5)
lbl_temp = tk.Label(master=frm_entry, text="\N{DEGREE FAHRENHEIT}")

# Layout the temperature Entry and Label in frm_entry
# using the .grid() geometry manager
ent_temperature.grid(row=0, column=0, sticky="e")
lbl_temp.grid(row=0, column=1, sticky="w")

# Create the conversion Button and result display Label
btn_convert = tk.Button(
    master=window,
    text="\N{RIGHTWARDS BLACK ARROW}",
    command=fahrenheit_to_celsius,
    bg="yellow"
)
lbl_result = tk.Label(master=window, text=" \N{DEGREE CELSIUS}", bg="lightblue",
                      width=7)

btn_clear = tk.Button(text="Reset")
#ent_temperature.entry.delete(0, tk.end)

# Set-up the layout using the .grid() geometry manager
frm_entry.grid(row=0, column=0, padx=10)
btn_convert.grid(row=0, column=1, pady=10)
lbl_result.grid(row=0, column=2, padx=15)
btn_clear.grid(row=0, column=3, padx=10)

# Run the application
window.mainloop()
```

<hr>

Real python Code:
```
import tkinter as tk

def fahrenheit_to_celsius():
    """Convert the value for Fahrenheit to Celsius and insert the
    result into lbl_result.
    """
    fahrenheit = ent_temperature.get()
    celsius = (5/9) * (float(fahrenheit) - 32)
    lbl_result["text"] = f"{round(celsius, 2)} \N{DEGREE CELSIUS}"

# Set-up the window
window = tk.Tk()
window.title("Temperature Converter")
window.resizable(width=False, height=False)

# Create the Fahrenheit entry frame with an Entry
# widget and label in it
frm_entry = tk.Frame(master=window)
ent_temperature = tk.Entry(master=frm_entry, width=10)
lbl_temp = tk.Label(master=frm_entry, text="\N{DEGREE FAHRENHEIT}")

# Layout the temperature Entry and Label in frm_entry
# using the .grid() geometry manager
ent_temperature.grid(row=0, column=0, sticky="e")
lbl_temp.grid(row=0, column=1, sticky="w")

# Create the conversion Button and result display Label
btn_convert = tk.Button(
    master=window,
    text="\N{RIGHTWARDS BLACK ARROW}",
    command=fahrenheit_to_celsius
)
lbl_result = tk.Label(master=window, text="\N{DEGREE CELSIUS}")

# Set-up the layout using the .grid() geometry manager
frm_entry.grid(row=0, column=0, padx=10)
btn_convert.grid(row=0, column=1, pady=10)
lbl_result.grid(row=0, column=2, padx=10)

# Run the application
window.mainloop()
```

<hr>

Any help, (or guidance where to find the answer), figuring out the **Reset** button I want would be appreciated. It is a slow process, but I do feel like I am making some headway.

<center><sub>Tiny Picture links back to my blog:</sub></center><center><a href="https://peakd.com/@bashadow"><img src=https://images.hive.blog/100x50/https://files.peakd.com/file/peakd-hive/bashadow/CSiw0Xl5-avatar3.png></a></center>

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