Python 基数36编码

Question

我该如何在Python中将一个整数用36进制编码，然后再解码回去呢？

Answer 1

from numpy import base_repr

num = base_repr(num, 36)
num = int(num, 36)

这里有关于 numpy.base_repr 的信息。

Answer 2

我真希望我早些看到这个。下面是答案：

def base36encode(number):
    if not isinstance(number, (int, long)):
        raise TypeError('number must be an integer')
    is_negative = number < 0
    number = abs(number)

    alphabet, base36 = ['0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ', '']

    while number:
        number, i = divmod(number, 36)
        base36 = alphabet[i] + base36
    if is_negative:
        base36 = '-' + base36

    return base36 or alphabet[0]


def base36decode(number):
    return int(number, 36)

print(base36encode(1412823931503067241))
print(base36decode('AQF8AA0006EH'))
assert(base36decode(base36encode(-9223372036721928027)) == -9223372036721928027)

Answer 3

你试过维基百科上的示例代码吗？

def base36encode(number, alphabet='0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'):
    """Converts an integer to a base36 string."""
    if not isinstance(number, int):
        raise TypeError('number must be an integer')
 
    base36 = ''
    sign = ''
 
    if number < 0:
        sign = '-'
        number = -number
 
    if 0 <= number < len(alphabet):
        return sign + alphabet[number]
 
    while number != 0:
        number, i = divmod(number, len(alphabet))
        base36 = alphabet[i] + base36
 
    return sign + base36
 
def base36decode(number):
    return int(number, 36)
 
print(base36encode(1412823931503067241))
print(base36decode('AQF8AA0006EH'))