user input value to use as decimal value python

Question

I am writing a python code where I ask the user for input and then I have to use their input to give the number of decimal places for the answer to an expression.

Answer 1

Use string formatting and pass userDecimals to the precision part of the format specifier:

>>> import math
>>> userDecimals = 6
>>> '{:.{}f}'.format(math.sqrt(1 - .1 **2), userDecimals)
'0.994987'
>>> userDecimals = 10
>>> '{:.{}f}'.format(math.sqrt(1 - .1 **2), userDecimals)
'0.9949874371'