Using root.update to print a string list in python once

Question

I am attempting to make a rogue clone in python using Tkinter, I found using .update would work better for what I want to do but unfortunately when I print out the string, it prints it out, and out and out

while True:
    print(key_press)
    if key_press == "d":
        current_player_col += 1

map_layout[current_player_col][current_player_row] = "P"
    
    map_layout_printable = ""
    
    for row in range(len(map_layout)):
        for column in range(len(map_layout[row])):
            map_layout_printable += map_layout[row][column]
        map_layout_printable += "\n"


    message = tk.Label(root, text=map_layout_printable)
    message.pack()
    root.update()

Is there a way of being able to update the string without printing it out over and over again?

What do you mean by "print it out"? There are no print statements in the code you provided. — Bryan Oakley, Mar 30 '22 at 16:47

TheEngineerGuy · Answer 1 · 2022-03-31T02:18:01.793

There are mulitple things that could be fixed with your code.

window = tk.Label(root, text="")
window.pack()


width = 8
height = 8

mp = [["0" for i in range(width)] for i in range(height)]

keypress = None #For now

def convertMapToText(mp1: list) -> str:
    strs = []
    for row in mp1:
        strs.append("".join(row)+"\n")

    return "".join(strs)


while True:
    print(keypress)
    #key input handler here

    window["text"] = convertMapToText(mp)

    root.update()

#1 : Use <labelObject>["text"]. This will let you modify the text in the widget in a much more clean and performance-friendly way.

#2 : Based on your code snippet, you shouldn't do for row in range(len(<list>)), this has significantly more function calls as well as more memory consumption. Do for row in <list>. This sets row to the row the loop is currently iterating through. For example...

lst = [[0 for i in range(4)] for e in range(4)]
for row in lst:
    print(row)

This code bit would print this...

[0,0,0,0]
[0,0,0,0]
[0,0,0,0]
[0,0,0,0]

#3 : I added a convertMapToText function which cleaned up and organized your code. This isn't entirely necessary but it made it much more readable. It is good practice to put algorithms in functions to clean up and organize your code or if your going to use a loop of any sort.

#4 : To prevent confusion, when you put a for loop in a list, it allows you to more efficiently fill a list or matrix (a list of lists in this case) without needing to call extra functions or increase your memory footprint.

#5 : Also, at line 6 in your code snippet, you will get thrown a IndentationError because it doesn't match the indentation of the lines around it as well as it being in a while loop block. Python is dependent on indentation. If you put in improper indentation, you are going to get an error.

As for the main part of your question, I assume you mean the variable keypress keeps printing. This is because it is in a while loop. If this is not the case, then I am unsure. Your code lacks any other print statements.

score 0 · Answer 2 · answered Mar 30 '22 at 17:06

You have your print statement inside your while loop without a break condition. If you are looking for something that runs until a condition is met you need something like this to stop it from printing once the condition is met. Your statement perpetually evaluates to True so it will just keep printing whatever key_press value is. The print statement needs to be after the condition.

data = [1, 2, 3, 4]


while True:
    item = int(input("Enter a number:"))
    if item in data:
        print("Found!")
        break
    else:
        print("Not Found")

Using root.update to print a string list in python once

2 Answers2