Python数学范围错误

Question

尝试在 Python 中计算非常大的数字时出现错误。这是我的代码:

# Where fourthNumber = 2790
# and dee = 413
emm = math.pow(fourthNumber, dee)

我的错误是:

line 44, in <module>
    emm = math.pow(fourthNumber, dee)
OverflowError: math range error

有解决这个错误的方法吗？我以为 Python 可以处理任意大的数字？还是我错了？任何帮助表示赞赏。谢谢!

Answer 1

问题是 math.pow(..) 适用于 float 。在 Python 中， float 不是任意大的。只有 int 是(在 python-3.x 中，long 在 python-2.x 中)。

但是，如果两个数字是整数，您可以使用 ** 运算符执行整数幂(当然，参数是整数):

>>> 2790**413
10827693458027068918752254513689369927451498632867702850871449492721716762882046359646654407147290095143376244612860740505063304616869045757879636651922242895944635094287526023557872050108996014618928707382416906723717536207944990935946477343103732942220495426003253324856391048675505527041527544249845903325107575822015010197006079682477544271998209608154757421132764034059289159228295810448568286783859864141487725512980856505994152145510660350938086763233208252511256291934375881870590480237727775536326670654123168787472077359939510018827829233028430183558108518520524567765780717109616748933630364200317687291046055118737587697510939517252245710306646155772831436013971724481443654932630319085588147436112198934867224850036968074130558127066188475740553149587714112808551835880666012903651859580234129805580074844684526620091506655345299434455806896837926335229779632528684030400890708579038639280240022309690038032176604539091205540422068492362106868171343650410145963283813864374487990607671475570427243900000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

但是，如果您将其转换为float，您会得到:

>>> float(2790**413)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OverflowError: int too large to convert to float

因此错误清楚地表明 python 无法将如此大的数字作为 float 来处理。