Function to determine if two numbers are nearly equal when rounded to n significant decimal digits

Question

I have been asked to test a library provided by a 3rd party. The library is known to be accurate to n significant figures. Any less-significant errors can safely be

Answer 1

"Significant figures" in decimal is a matter of adjusting the decimal point and truncating to an integer.

>>> int(3.1415926 * 10**3)
3141
>>> int(1234567 * 10**-3)
1234
>>>