How can I get first first N decimal digits of a float represented as an int?

Question

For example, if I have:

12.43564

I'd like to be able to get 43564 as an int. Or, if the float has many decimal places, it would be OK to just get the first N decimals as integer. For example, if N is 3, for 12.43564 I would then get 435. Unfortunately, I cannot just convert the number to a string as I need to use this in a numba compiled function, where the conversion of a float to a string is not possible as per this open issue.

Is there a way to do this?

Answer 1

Typecast it to a string, split on the period, get the N digits you want.

>>> x = 1.23456789
str(x)
>>> str(x)
'1.23456789'
>>> str(x).split('.')
['1', '23456789']
>>> str(x).split('.')[1][:4]
'2345'

Based on edit,

Substract the int part. Multiply by 10000 to get the first 4.

>>> (x - int(x)) * 10000
2345.678899999999
>>> int((x - int(x)) * 10000)
2345