math.log(x) returns unexpected results in Python
Question: I am attempting to do some basic dB calculations using Python. If I use either
Excel or a scientific calculator:

    
    
    20*log(0.1) = -20
    

in Python:

    
    
    20*log(0.1) = -46.0517018599
    

to simplify further, Excel and Scientific calc:

    
    
    log(0.1) = -1
    

Python:

    
    
    log(0.1) = -2.30258509299
    

I start my script with

    
    
    import math
    
    log = math.log
    

Can someone explain why this is and how I can fix it?


Answer: `math.log` is actually `ln` (with a base of _e_). To get the expected results,
use `math.log(0.1, 10)` or `math.log10(0.1)`.

