Python TKInter Problem

file1.py

import tkinter as tk
import secondFile as f2

bool = False
# This isn't executed.
if bool:
    print("Secon Window")
    f2.showUp()

root = tk.Tk()

label = tk.Label(text="Hello! I'm first window!", font=("SEGOEUIL", "20", "bold"))
label.pack()

# But this casues window from secondFile.py to open, instead of only opening window from this file
root.mainloop()

secondFile.py

import tkinter as tk

win = tk.Tk()

label = tk.Label(
    master=win, text="Hello! I'm second window!", font=("SEGOEUIL", "20", "bold")
)
label.pack()


def showUp():
    print("Welcome!")
    win.mainloop()