Problem with codeacademy python exercise

Write a function called censor that takes two strings, text and word, as input. It should return the text with the word you chose replaced with asterisks.

def censor(text, word):
result = []
for i in range(len(text.split())):
    if text.split()[i] == 'word': 
        result.append("*" * len(text.split()[i]))
    else:
        result.append(text.split()[i])        
return " ".join(result)

censor("hey hey hey", "hey") returns "hey hey hey" instead of "* * ***". Been looking at this for half an hour and cannot understand what goes wrong. I am absolutely new to programming so any pointer ( no punt intended ) or suggestion is welcome.