import tkinter
import pyodbc

conn = pyodbc.connect("Driver={SQL Server Native Client 11.0};"
                      "Server=ORSA\SQLEXPRESS;"
                      "Database=ACDB;"
                      "Trusted_Connection=yes;")

def submit_12():
    cursor = conn.cursor()
    cursor.execute('''
                       UPDATE ACDB.dbo.packages
                       SET speed = spe.get
                       WHERE pack_id = pac.get''')

    conn.commit()


window = tkinter.Tk()
window.title("GUI")
tkinter.Label(window, text="Pack ID").grid(row=0)
pac=tkinter.Entry(window)
pac.grid(row=0, column=1)

tkinter.Label(window, text="Speed").grid(row=1)
spe=tkinter.Entry(window)
spe.grid(row=1, column=1)

tkinter.Label(window, text="start date").grid(row=2)
startdate=tkinter.Entry(window)
startdate.grid(row=2, column=1)

tkinter.Button(window, text = "Quit", command=window.quit).grid(row=3, column=0)
tkinter.Button(window, text = "Submit", command=submit_12).grid(row=3, column=1)


window.mainloop()

Error:
Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Program Files (x86)\Python37-32\lib\tkinter\__init__.py", line 1705, in __call__
    return self.func(*args)
  File "C:/Users/OrSa/Desktop/אקדא10000.py", line 15, in submit_12
    WHERE pack_id = pac.get''')
pyodbc.ProgrammingError: ('42000', '[42000] [Microsoft][SQL Server Native Client 11.0][SQL Server]The multi-part identifier "pac.get" could not be bound. (4104) (SQLExecDirectW)')