need help what is the error here

[m123]

i am trying to find the cube root and print

cube=-64
for i in range(abs(cube)+1):
    if i**3 >=abs(cube):
	break
if i**3 !=abs(cube):
	print(cube," is not a perfect cube")
else:
   if  cube<0:
     	i = -i
    print('Cube root of ' + str(cube) + ' is ' + str(cube))

error is line no 4

Error:
C:\Users\solas\Documents>cubert.py
  File "C:\Users\s\Documents\cubert.py", line 4
    passed all potential cube roots
             ^
SyntaxError: invalid syntax

1)sure there is a syntax error ?
2) here "i" i in range in line no 2 , does it initializes to zero for first iteration.Could you please explain the control how it is passing line by line