当我运行代码时
a = 2**(2028/2)*1023
print("a is",a)
b = 2**(2029/2)*1023
print("b is",b)
c = 2**(2028/2)*1024
print("c is",c)
d = 2**(1014)*1024
print("d is",d)
e = 2**(2048)
print("e is",e)
g = 2**(1024)
print("g is",g)
h = 2**(2048/2)
print("h is",h)
输出是:
a is 1.795937575160302e+308
b is inf
c is inf
d is 179769313486231590772930519078902473361797697894230657273430081157732675805500963132708477322407536021120113879871393357658789768814416622492847430639474124377767893424865485276302219601246094119453082952085005768838150682342462881473913110540827237163350510684586298239947245938479716304835356329624224137216
e is 32317006071311007300714876688669951960444102669715484032130345427524655138867890893197201411522913463688717960921898019494119559150490921095088152386448283120630877367300996091750197750389652106796057638384067568276792218642619756161838094338476170470581645852036305042887575891541065808607552399123930385521914333389668342420684974786564569494856176035326322058077805659331026192708460314150258592864177116725943603718461857357598351152301645904403697613233287231227125684710820209725157101726931323469678542580656697935045997268352998638215525166389437335543602135433229604645318478604952148193555853611059596230656
g is 179769313486231590772930519078902473361797697894230657273430081157732675805500963132708477322407536021120113879871393357658789768814416622492847430639474124377767893424865485276302219601246094119453082952085005768838150682342462881473913110540827237163350510684586298239947245938479716304835356329624224137216
Traceback (most recent call last):
File "newfile.py", line 19, in <module>
h = 2**(2048/2)
OverflowError: (34, 'Result too large')
c 应该与 d 相同,但实际上不是。 g 和 h 相同。为什么?是否有一种解决方法可以让您准确计算 2**(2048/2)
和 2**(2028/2)*1024
?我不认为 2048 太大了,因为 e 计算没有任何错误。
最佳答案
区别在于 2048/2
是一个 float ,而不是一个整数。因此,结果将被评估为 float ,而 float 的范围有限。
因此:
>>> 2**1024.0
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
OverflowError: (34, 'Result too large')
>>> 2**1024
179769313486231590772930519078902473361797697894230657273430081157732675805500963132708477322407536021120113879871393357658789768814416622492847430639474124377767893424865485276302219601246094119453082952085005768838150682342462881473913110540827237163350510684586298239947245938479716304835356329624224137216
>>> float(2**1024)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
OverflowError: int too large to convert to float
但是,如果你只使用整数:
>>> 2**(2048//2)
179769313486231590772930519078902473361797697894230657273430081157732675805500963132708477322407536021120113879871393357658789768814416622492847430639474124377767893424865485276302219601246094119453082952085005768838150682342462881473913110540827237163350510684586298239947245938479716304835356329624224137216
关于python - 为什么 2**1024 工作而 2**(2048/2) 导致 OverflowError?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/58733710/