Question

I’ve been experimenting with the standard python math module and have come across some subtle difficulties. For example, I’m noticing the following behavior concerning indeterminate forms:

0**0

>>> 1

def inf():
    return 1e900
    # Will return inf

inf()**inf()

>>> inf

And other anomalies of the sort. I’m writing a calculator, and I’d like to have it be mathematically accurate. Is there something I can do about this? Or, is there some way to circumvent this? Thanks in advance.

Answer 1

There’s nothing wrong with your first example. 0**0 is often defined to be 1.

The second example is all to do with precision of doubles. 1E900 exceeds the maximum positive value of a (most likely 64-bit) double. If you want doubles outside of that range, you’ll have to look into libraries. Fortunately Python has one built-in: the decimal module.

For example:

from decimal import Decimal
d = Decimal('1E900')
f = d + d
print(f)
>>> 2E900