Round a float to same decimals as the multiplier

Question

I'd like someone's help in writing this in the most pythonic way possible

x = 2.651
y = 1.05
a = x * y
print(a)
2.78355

In this example, I want a to have the same number of decimals as x , so the answer should be 2.784. What is a pythonic way to get to this answer with the right number of decimals?

Answer 1

Try something like this. My trick uses string properties.

x = 2.651
y = 1.05

x_dec = len(str(x).split('.')[1])

a = ('{0:.%df}' % x_dec).format(x * y)

Answer 2

x = 2.651
decloc = (str(x).find('.'))+1
decimals = (len(str(x)[decloc:]))
y = 1.05
a = x * y
print(round(a, decimals))