# open_file = filedialog.askopenfilenames(filetypes=[("File type", "Image's .extesnions spearated by space")])
# In this example I'll be opening dialog box to select only images with (.jpg, .jpeg, .png, .jfif) extensions.
>>> from tkinter import Tk, filedialog
>>> 
>>> root = Tk() # pointing root to Tk() to use it as Tk() in program.
>>> root.withdraw() # Hides small tkinter window.
''
>>> root.attributes('-topmost', True) # Opened windows will be active. above all windows despite of selection.
''
>>># Open dialog box to select images with certain extensions.
>>> open_file = filedialog.askopenfilenames(filetypes=[("Image Files", ".png .jfif, .jpg, .jpeg")]) # returns a tuple with opened file's complete path
>>> print(open_file)
('C:/Users/User/OneDrive/Documents/Images/Image (1).png', 'C:/Users/User/OneDrive/Documents/Images/Image (2).jpeg', 'C:/Users/User/OneDrive/Documents/Images/Image (3).jpg', 'C:/Users/User/OneDrive/Documents/Images/Image (4).png', 'C:/Users/User/OneDrive/Documents/Images/Image (5).jfif')