Why does my code work occasionally?

Question

Created a python code to make random quotes that sound deep but it only works some of the time. Not sure why, so any help is appreciated.
https://code.sololearn.com/cYkgIIB9MZjG/?ref=app

Answer 1

I think You should write
for i in range(random.randint(1,19)):
Because there 18 words in Array.
And there will be random words in random length with in array.

Answer 2

The code is perfect. I tried in Vs code and it worked perfectly. Maybe a problem in Sololearn Code Playground