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@xv
Last active April 2, 2023 17:46
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Python function to calculate the check digit of a UPC-12 barcode.
def calc_check_digit(digits):
digits = [int(i) for i in str(digits)][:-1]
odd_pos_list = digits[0::2] # 1st, 3rd, 5th, etc
even_pos_list = digits[1::2] # 2nd, 4th, 6th, etc
n = (sum(odd_pos_list) * 3) + sum(even_pos_list)
rmndr = n % 10
return (10 - rmndr) if rmndr > 0 else 0
# Full 12 digits of a UPC-12 barcode
digits = '123601057072'
check_digit = calc_check_digit(digits)
# Return value should match the 12th digit on the barcode
print(check_digit)
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