Source Code:
# Python Program to calculate the square root
num = float(input('Enter a number: '))
num_sqrt = num ** 0.5
print('The square root of %0.3f is %0.3f'%(num ,num_sqrt))
Output:
Enter a number: 8 The square root of 8.000 is 2.828
In this program, we ask the user for a number and find the square root using the ** exponent operator. This program works for all positive real numbers. But for negative or complex numbers, it can be done as follows.
Source Code:
# Find square root of real or complex numbers
# Import the complex math module
import cmath
num = eval(input('Enter a number: '))
num_sqrt = cmath.sqrt(num)
print('The square root of {0} is {1:0.3f}+{2:0.3f}j'.format(num ,num_sqrt.real,num_sqrt.imag))
Output:
Enter a number: 1+2j The square root of (1+2j) is 1.272+0.786j
In this program, we use the sqrt() function in the cmath (complex math) module. Notice that we have used the eval() function instead of float() to convert complex number as well. Also notice the way in which the output is formatted. Look here for more about string formatting in Python.