I have an array of phrases:

bannedWords = ['hi', 'hi you', 'hello', 'and you']

I want to take a sentence like "hi, how are tim and you doing" and get this:

", how are tim doing"

Exact case matching is OK - sorry, should have clarified.

Since you want to remove extra spaces as well, the regex below should work better:

s = "Hi, How are Tim and you doing"
bannedWords = ['hi', 'hi you', 'hello', 'and you']
for i in bannedWords: s = re.sub(i + "\s*", '', s, flags = re.I)
print s
# ', How are Tim doing'