Simpler method: Decimal to Binary conversion

Script

#!/usr/local/bin/python3.7

print()
inflow = int(input("Please enter a number between 0 and 1023: "))
print()

binary_string = ''

if 0 <= inflow <= 1024:
    binary_string = binary_string + str(inflow//512)
    inflow = inflow % 512
    binary_string = binary_string + str(inflow//256)
    inflow = inflow % 256
    binary_string = binary_string +str(inflow//128)
    inflow = inflow % 128
    binary_string = binary_string + str(inflow//64)
    inflow = inflow % 64
    binary_string = binary_string + str(inflow//32)
    inflow = inflow % 32
    binary_string = binary_string + str(inflow//16)
    inflow = inflow % 16
    binary_string = binary_string + str(inflow//8)
    inflow = inflow %8
    binary_string = binary_string + str(inflow//4)
    inflow = inflow % 4
    binary_string = binary_string + str(inflow//2)
    inflow = inflow % 2
    binary_string = binary_string + str(inflow)

if binary_string != '':
    print(binary_string)
else:
    print("Invalid data.")
print()


Execution

Please enter a number between 0 and 1023: 649

1010001001


Please enter a number between 0 and 1023: 111

0001101111


Please enter a number between 0 and 1023: 971

1111001011