My own solution to Kompas coding test http://bit.ly/2cnvywQ

kompas.py

#!/usr/bin/python

maxw=25    # largest width
minw=1     # smallest width
pad=1      # left-right padding per step
incr=pad*2 #

# assumptions
assert maxw >= minw + 2 # max width must be equals or greater than minw+2
assert minw > 0
assert maxw > 0
assert maxw % 2 == 1    # max width must be an odd number
assert minw % 2 == 1    # min width must be an odd number

for linew in range(maxw, minw-1, -incr) + range(minw+incr, maxw+1, incr):
    indent = (maxw - linew) / 2
    print (' ' * indent) + ('*' * linew)