You can just go at the root a bunch of times:

S = 1234 # Any number you like  
 
ans = S/2 
x = 0.0 
for _ in range(64):  
   ans = (ans + x)/2  
   x = S / ans  
print(f"The square root of {S} is {ans:.7f}") 

Output:

The square root of 1234 is 35.1283361 

And:

The square root of 2 is 1.4142136