python bit_length() of 0 returns 意外值

Question

为什么 0 return 的位长是 0 而不是 1？

>>> int(0).bit_length()
0

>>> int(2).bit_length()
2

2 在二进制中是 0x10，表示两位，二进制中的零在技术上仍然占用 1 位，因为它在十六进制中的表示是 0x0?

Answer 1

Python 文档指出

More precisely, if x is nonzero, then x.bit_length() is the unique positive integer k such that 2**(k-1) <= abs(x) < 2**k. Equivalently, when abs(x) is small enough to have a correctly rounded logarithm, then k = 1 + int(log(abs(x), 2)).
If x is zero, then x.bit_length() returns 0.

https://docs.python.org/3/library/stdtypes.html#int.bit_length

Answer 2

请阅读 https://docs.python.org/3/library/stdtypes.html 上的文档它被解释。这就是该功能的工作原理。如果你发送 0，它会输出 0

If x is zero, then x.bit_length() returns 0.

python bit_length() of 0 returns 意外值

python bit_length() of 0 returns unexpected value

python

binary

bit