Python - 如何始终生成有效的 Luhn 数？
Python - How to always generate valid Luhn numbers?
我正在尝试使用随机库生成有效的 Luhn 数（不使用 fast_luhn 等其他库）
我生成一个随机数，然后最后一位从0迭代到9，每次迭代都是一个新的案例来检查函数valid_luhn，然后与生成的第一个数字的下一位相同，但是我得到了坚持这个指数、随机和分支的想法。
这是我使用 Luhn 算法验证数字的代码（如果您有任何改进建议，例如使用更好的列表理解，请告诉我）：
def valid_luhn(cc):
num = list(map(int, str(cc)))
return sum(num[::-2] + [sum(divmod(d * 2, 10)) for d in num[-2::-2]]) % 10 == 0
这是我的信用卡号生成器。它会要求您提供真实卡的前 15 位数字，以便生成的号码将由同一家金融机构 "issued"：
from random import randint
cc_number = []
multiplied_by_two = []
remaining_numbers = []
new_number = ''
# Ask for a first 15 digits of a card
starting_15 = input('Enter first 15 digits: ')
z = 0
y = 0
while z < 25:
for i in str(starting_15):
cc_number.append(int(i))
# extract all the numbers that have to be multiplied by 2
for i in cc_number[0:16:2]:
i *= 2
if len(str(i)) == 2: # check if the multiplied number is a two digit number
for x in str(i): # if it is, separate them, and add them together
y += int(str(x))
i = y
multiplied_by_two.append(i)
y = 0
for i in cc_number[1:15:2]: # extract remaining numbers
remaining_numbers.append(i)
# Luhn's algorithm
last_digit = ((sum(multiplied_by_two) + sum(remaining_numbers)) * 9) % 10
for i in cc_number:
new_number += str(i)
print(new_number + str(last_digit))
cc_number = []
multiplied_by_two = []
remaining_numbers = []
new_number = ''
starting_15 = int(starting_15) + randint(-15, 25)
z += 1
希望对您有所帮助！
第一个解法：
from random import randint
def generate_card(type):
"""
Prefill some values based on the card type
"""
card_types = ["americanexpress","visa13", "visa16","mastercard","discover"]
def prefill(t):
# typical number of digits in credit card
def_length = 16
"""
Prefill with initial numbers and return it including the total number of digits
remaining to fill
"""
if t == card_types[0]:
# american express starts with 3 and is 15 digits long
# override the def lengths
return [3, randint(4,7)], 13
elif t == card_types[1] or t == card_types[2]:
# visa starts with 4
if t.endswith("16"):
return [4], def_length - 1
else:
return [4], 12
elif t == card_types[3]:
# master card start with 5 and is 16 digits long
return [5, randint(1,5)], def_length - 2
elif t == card_types[4]:
# discover card starts with 6011 and is 16 digits long
return [6, 0, 1, 1], def_length - 4
else:
# this section probably not even needed here
return [], def_length
def finalize(nums):
"""
Make the current generated list pass the Luhn check by checking and adding
the last digit appropriately bia calculating the check sum
"""
check_sum = 0
#is_even = True if (len(nums) + 1 % 2) == 0 else False
"""
Reason for this check offset is to figure out whether the final list is going
to be even or odd which will affect calculating the check_sum.
This is mainly also to avoid reversing the list back and forth which is specified
on the Luhn algorithm.
"""
check_offset = (len(nums) + 1) % 2
for i, n in enumerate(nums):
if (i + check_offset) % 2 == 0:
n_ = n*2
check_sum += n_ -9 if n_ > 9 else n_
else:
check_sum += n
return nums + [10 - (check_sum % 10) ]
# main body
t = type.lower()
if t not in card_types:
print("Unknown type: '%s'" % type)
print("Please pick one of these supported types: %s" % card_types)
return
initial, rem = prefill(t)
so_far = initial + [randint(1,9) for x in range(rem - 1)]
print ("Card type: %s, " % t,)
print ("".join(map(str,finalize(so_far))))
# run - check
generate_card("discover")
generate_card("mastercard")
generate_card("americanexpress")
generate_card("visa13")
generate_card("visa16")
第二种方案：
from random import Random
import copy
visaPrefixList = [
['4', '5', '3', '9'],
['4', '5', '5', '6'],
['4', '9', '1', '6'],
['4', '5', '3', '2'],
['4', '9', '2', '9'],
['4', '0', '2', '4', '0', '0', '7', '1'],
['4', '4', '8', '6'],
['4', '7', '1', '6'],
['4']]
mastercardPrefixList = [
['5', '1'], ['5', '2'], ['5', '3'], ['5', '4'], ['5', '5']]
amexPrefixList = [['3', '4'], ['3', '7']]
discoverPrefixList = [['6', '0', '1', '1']]
dinersPrefixList = [
['3', '0', '0'],
['3', '0', '1'],
['3', '0', '2'],
['3', '0', '3'],
['3', '6'],
['3', '8']]
enRoutePrefixList = [['2', '0', '1', '4'], ['2', '1', '4', '9']]
jcbPrefixList = [['3', '5']]
voyagerPrefixList = [['8', '6', '9', '9']]
def completed_number(prefix, length):
"""'prefix' is the start of the CC number as a string, any number of digits.
'length' is the length of the CC number to generate. Typically 13 or 16"""
ccnumber = prefix
# generate digits
while len(ccnumber) < (length - 1):
digit = str(generator.choice(range(0, 10)))
ccnumber.append(digit)
# Calculate sum
sum = 0
pos = 0
reversedCCnumber = []
reversedCCnumber.extend(ccnumber)
reversedCCnumber.reverse()
while pos < length - 1:
odd = int(reversedCCnumber[pos]) * 2
if odd > 9:
odd -= 9
sum += odd
if pos != (length - 2):
sum += int(reversedCCnumber[pos + 1])
pos += 2
# Calculate check digit
checkdigit = ((sum / 10 + 1) * 10 - sum) % 10
ccnumber.append(str(checkdigit))
return ''.join(ccnumber)
def credit_card_number(rnd, prefixList, length, howMany):
result = []
while len(result) < howMany:
ccnumber = copy.copy(rnd.choice(prefixList))
result.append(completed_number(ccnumber, length))
return result
def output(title, numbers):
result = []
result.append(title)
result.append('-' * len(title))
result.append('\n'.join(numbers))
result.append('')
return '\n'.join(result)
#
# Main
#
generator = Random()
generator.seed() # Seed from current time
mastercard = credit_card_number(generator, mastercardPrefixList, 16, 10)
print(output("Mastercard", mastercard))
visa16 = credit_card_number(generator, visaPrefixList, 16, 10)
print(output("VISA 16 digit", visa16))
visa13 = credit_card_number(generator, visaPrefixList, 13, 5)
print(output("VISA 13 digit", visa13))
amex = credit_card_number(generator, amexPrefixList, 15, 5)
print(output("American Express", amex))
# Minor cards
discover = credit_card_number(generator, discoverPrefixList, 16, 3)
print(output("Discover", discover))
diners = credit_card_number(generator, dinersPrefixList, 14, 3)
print(output("Diners Club / Carte Blanche", diners))
enRoute = credit_card_number(generator, enRoutePrefixList, 15, 3)
print(output("enRoute", enRoute))
jcb = credit_card_number(generator, jcbPrefixList, 16, 3)
print(output("JCB", jcb))
voyager = credit_card_number(generator, voyagerPrefixList, 15, 3)
print(output("Voyager", voyager))
我正在尝试使用随机库生成有效的 Luhn 数（不使用 fast_luhn 等其他库）
我生成一个随机数，然后最后一位从0迭代到9，每次迭代都是一个新的案例来检查函数valid_luhn，然后与生成的第一个数字的下一位相同，但是我得到了坚持这个指数、随机和分支的想法。
这是我使用 Luhn 算法验证数字的代码（如果您有任何改进建议，例如使用更好的列表理解，请告诉我）：
def valid_luhn(cc):
num = list(map(int, str(cc)))
return sum(num[::-2] + [sum(divmod(d * 2, 10)) for d in num[-2::-2]]) % 10 == 0
这是我的信用卡号生成器。它会要求您提供真实卡的前 15 位数字，以便生成的号码将由同一家金融机构 "issued"：
from random import randint
cc_number = []
multiplied_by_two = []
remaining_numbers = []
new_number = ''
# Ask for a first 15 digits of a card
starting_15 = input('Enter first 15 digits: ')
z = 0
y = 0
while z < 25:
for i in str(starting_15):
cc_number.append(int(i))
# extract all the numbers that have to be multiplied by 2
for i in cc_number[0:16:2]:
i *= 2
if len(str(i)) == 2: # check if the multiplied number is a two digit number
for x in str(i): # if it is, separate them, and add them together
y += int(str(x))
i = y
multiplied_by_two.append(i)
y = 0
for i in cc_number[1:15:2]: # extract remaining numbers
remaining_numbers.append(i)
# Luhn's algorithm
last_digit = ((sum(multiplied_by_two) + sum(remaining_numbers)) * 9) % 10
for i in cc_number:
new_number += str(i)
print(new_number + str(last_digit))
cc_number = []
multiplied_by_two = []
remaining_numbers = []
new_number = ''
starting_15 = int(starting_15) + randint(-15, 25)
z += 1
希望对您有所帮助！
第一个解法：
from random import randint
def generate_card(type):
"""
Prefill some values based on the card type
"""
card_types = ["americanexpress","visa13", "visa16","mastercard","discover"]
def prefill(t):
# typical number of digits in credit card
def_length = 16
"""
Prefill with initial numbers and return it including the total number of digits
remaining to fill
"""
if t == card_types[0]:
# american express starts with 3 and is 15 digits long
# override the def lengths
return [3, randint(4,7)], 13
elif t == card_types[1] or t == card_types[2]:
# visa starts with 4
if t.endswith("16"):
return [4], def_length - 1
else:
return [4], 12
elif t == card_types[3]:
# master card start with 5 and is 16 digits long
return [5, randint(1,5)], def_length - 2
elif t == card_types[4]:
# discover card starts with 6011 and is 16 digits long
return [6, 0, 1, 1], def_length - 4
else:
# this section probably not even needed here
return [], def_length
def finalize(nums):
"""
Make the current generated list pass the Luhn check by checking and adding
the last digit appropriately bia calculating the check sum
"""
check_sum = 0
#is_even = True if (len(nums) + 1 % 2) == 0 else False
"""
Reason for this check offset is to figure out whether the final list is going
to be even or odd which will affect calculating the check_sum.
This is mainly also to avoid reversing the list back and forth which is specified
on the Luhn algorithm.
"""
check_offset = (len(nums) + 1) % 2
for i, n in enumerate(nums):
if (i + check_offset) % 2 == 0:
n_ = n*2
check_sum += n_ -9 if n_ > 9 else n_
else:
check_sum += n
return nums + [10 - (check_sum % 10) ]
# main body
t = type.lower()
if t not in card_types:
print("Unknown type: '%s'" % type)
print("Please pick one of these supported types: %s" % card_types)
return
initial, rem = prefill(t)
so_far = initial + [randint(1,9) for x in range(rem - 1)]
print ("Card type: %s, " % t,)
print ("".join(map(str,finalize(so_far))))
# run - check
generate_card("discover")
generate_card("mastercard")
generate_card("americanexpress")
generate_card("visa13")
generate_card("visa16")
第二种方案：
from random import Random
import copy
visaPrefixList = [
['4', '5', '3', '9'],
['4', '5', '5', '6'],
['4', '9', '1', '6'],
['4', '5', '3', '2'],
['4', '9', '2', '9'],
['4', '0', '2', '4', '0', '0', '7', '1'],
['4', '4', '8', '6'],
['4', '7', '1', '6'],
['4']]
mastercardPrefixList = [
['5', '1'], ['5', '2'], ['5', '3'], ['5', '4'], ['5', '5']]
amexPrefixList = [['3', '4'], ['3', '7']]
discoverPrefixList = [['6', '0', '1', '1']]
dinersPrefixList = [
['3', '0', '0'],
['3', '0', '1'],
['3', '0', '2'],
['3', '0', '3'],
['3', '6'],
['3', '8']]
enRoutePrefixList = [['2', '0', '1', '4'], ['2', '1', '4', '9']]
jcbPrefixList = [['3', '5']]
voyagerPrefixList = [['8', '6', '9', '9']]
def completed_number(prefix, length):
"""'prefix' is the start of the CC number as a string, any number of digits.
'length' is the length of the CC number to generate. Typically 13 or 16"""
ccnumber = prefix
# generate digits
while len(ccnumber) < (length - 1):
digit = str(generator.choice(range(0, 10)))
ccnumber.append(digit)
# Calculate sum
sum = 0
pos = 0
reversedCCnumber = []
reversedCCnumber.extend(ccnumber)
reversedCCnumber.reverse()
while pos < length - 1:
odd = int(reversedCCnumber[pos]) * 2
if odd > 9:
odd -= 9
sum += odd
if pos != (length - 2):
sum += int(reversedCCnumber[pos + 1])
pos += 2
# Calculate check digit
checkdigit = ((sum / 10 + 1) * 10 - sum) % 10
ccnumber.append(str(checkdigit))
return ''.join(ccnumber)
def credit_card_number(rnd, prefixList, length, howMany):
result = []
while len(result) < howMany:
ccnumber = copy.copy(rnd.choice(prefixList))
result.append(completed_number(ccnumber, length))
return result
def output(title, numbers):
result = []
result.append(title)
result.append('-' * len(title))
result.append('\n'.join(numbers))
result.append('')
return '\n'.join(result)
#
# Main
#
generator = Random()
generator.seed() # Seed from current time
mastercard = credit_card_number(generator, mastercardPrefixList, 16, 10)
print(output("Mastercard", mastercard))
visa16 = credit_card_number(generator, visaPrefixList, 16, 10)
print(output("VISA 16 digit", visa16))
visa13 = credit_card_number(generator, visaPrefixList, 13, 5)
print(output("VISA 13 digit", visa13))
amex = credit_card_number(generator, amexPrefixList, 15, 5)
print(output("American Express", amex))
# Minor cards
discover = credit_card_number(generator, discoverPrefixList, 16, 3)
print(output("Discover", discover))
diners = credit_card_number(generator, dinersPrefixList, 14, 3)
print(output("Diners Club / Carte Blanche", diners))
enRoute = credit_card_number(generator, enRoutePrefixList, 15, 3)
print(output("enRoute", enRoute))
jcb = credit_card_number(generator, jcbPrefixList, 16, 3)
print(output("JCB", jcb))
voyager = credit_card_number(generator, voyagerPrefixList, 15, 3)
print(output("Voyager", voyager))