[Python] Why my button starts the function without pressing it? [duplicate]

Why my button starts the imported funtion without pressing it, i think it's the arguments but they are necessary:

def getFile(self):
self.filename = filedialog.askopenfilename()
if len(self.filename) > 25:
layoutfilename = tk.Label(layoutframe, text=self.filename[25:])
layoutfilename.grid(column=2, row=0, sticky=tk.EW, padx=5, pady=5)
else:
layoutfilename = tk.Label(layoutframe, text=self.filename)
layoutfilename.grid(column=2, row=0, sticky=tk.EW, padx=5, pady=5)
encryptbutton = tk.Button(layoutframe, text="Encrypt File", command=encryption(self.filename))
encryptbutton.grid(column=3, row=0, padx=5, pady=5)

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