Tkinter "Label object is not callable"

I'm trying to set the text of a Tkinter label equal to the user input from an Entry object.

Here is the relevant code:

def Return(event):
    global Password
    global Input
    global SecurityLabel

    Password = Input.get()

    Parse(Password)
    Variations(Password)
    Search(Password)
    Additions(Password)
    Deductions(Password)
    CheckForAdjacency(ConvertToCoordinates(Password))
    MinimumRequirements(Password)

    print("Your password security rating is: " + str(Security))
    SecurityLabel['text'] = Security 

#GUI
MainWindow = Tk()
MainWindow.title("Password Assessor")
MainWindow.geometry("500x100")

TopMenu = Menu(MainWindow)
MainWindow.config(menu = TopMenu)

subMenu = Menu(TopMenu)
TopMenu.add_cascade(label="file", menu=subMenu)
subMenu.add_command(label="boop")

Label = Label(MainWindow, text="Please enter a password:")
Label.pack(fill = 'x')

SecurityLabel = Label(MainWindow, text="")
SecurityLabel.pack(fill = 'x')

Input = Entry(MainWindow, show="*")
Input.pack(fill = 'x')
Input.focus_set 

MainWindow.bind('<Return>', Return)

MainWindow.mainloop()

I grab the user's input when the return key is pressed from the entry box named Input with this code:

Password = Input.get()

I try to set the text of a label called SecurityLabel equal to the integer "Security" with this code:

SecurityLabel['text'] = Security 

The SecurityLabel is initialized with this code:

SecurityLabel = Label(MainWindow, text="")
SecurityLabel.pack(fill = 'x')

When I try to run the code, I get this error:

Traceback (most recent call last):
  File "/Users/kosay.jabre/Desktop/Password Assessor/Password.py", line 242, in <module>
    SecurityLabel = Label(MainWindow, text="")
TypeError: 'Label' object is not callable

I don't know what I'm doing wrong. How can I make this work? Please try to make your explanation simple.