Round to significant figures in python

Question

I want to round like this 42949672 -> 42949700, 2147483647 -> 2147480000, 4252017622 -> 4252020000 etc.

I tried to use following , but only works for the first one. How can I make a more general one? thanks

round(42949672, -2)

Answer 1

I assume you want to round to 6 significant figures. If you want to round ints, you can use

def round_sf(number, significant):
    return round(number, significant - len(str(number)))

print(round_sf(4252017622, 6))

Result:

4252020000