Pomodoro GUI application using python Tkinter

main.py

import math
from tkinter import *

# ---------------------------- CONSTANTS ------------------------------- #
PINK = "#e2979c"
RED = "#e7305b"
GREEN = "#9bdeac"
YELLOW = "#f7f5dd"
FONT_NAME = "Courier"
WORK_MIN = 25
SHORT_BREAK_MIN = 5
LONG_BREAK_MIN = 20
reps = 0
timer = ""


# ---------------------------- TIMER RESET ------------------------------- #

def reset_timer():
    window.after_cancel(timer)
    canvas.itemconfig(timer_text, text="00:00")
    timer_label.config(text="Timer")
    tick_label.config(text="")
    global reps
    reps = 0


# ---------------------------- TIMER MECHANISM ------------------------------- #
def start_timer():
    global reps
    reps += 1

    work_sec = WORK_MIN * 60
    short_break_sec = SHORT_BREAK_MIN * 60
    long_break_sec = LONG_BREAK_MIN * 60

    if reps % 8 == 0:
        count_down(long_break_sec)
        timer_label.config(text="Break", fg=RED)
    elif reps % 2 == 0:
        count_down(short_break_sec)
        timer_label.config(text="Break", fg=PINK)
    else:
        count_down(work_sec)
        timer_label.config(text="Work", fg=GREEN)


# ---------------------------- COUNTDOWN MECHANISM ------------------------------- #
def count_down(count):
    count_min = math.floor(count / 60)
    count_second = count % 60
    if count_second < 10:
        count_second = f"0{count_second}"
    canvas.itemconfig(timer_text, text=f"{count_min}:{count_second}")
    if count > 0:
        global timer
        timer = window.after(1000, count_down, count - 1)
    else:
        start_timer()
        marks = ""
        work_sessions = math.floor(reps / 2)
        for _ in range(work_sessions):
            marks += "🕉"
        tick_label.config(text=marks)


# ---------------------------- UI SETUP ------------------------------- #

window = Tk()
window.title("Pomodoro GUI")
window.config(padx=50, pady=50, bg=YELLOW)

canvas = Canvas(width=200, height=224, bg=YELLOW, highlightthickness=0)

tomato_image = PhotoImage(file="tomato.png")

canvas.create_image(100, 112, image=tomato_image)
# Below, we are assigning the canvas create text to a variable named timer_text to use in def function above
timer_text = canvas.create_text(100, 130, text="00:00", fill="white", font=(FONT_NAME, 35, "bold"))
canvas.grid(column=1, row=1)

# Challenge - Complete the Application's User Interface (UI)
timer_label = Label(text="Timer", font=(FONT_NAME, 50, "bold"), bg=YELLOW, fg=GREEN)
timer_label.grid(column=1, row=0)

start_button = Button(text="Start", command=start_timer, bg=YELLOW, fg="violet")
start_button.grid(column=0, row=2)

reset_button = Button(text="Reset", bg=YELLOW, fg="violet", command=reset_timer)
reset_button.grid(column=2, row=2)

tick_label = Label(bg=YELLOW, fg=GREEN)
tick_label.grid(column=1, row=3)

window.mainloop()