Can you explain this code
sentence= input(" enter a sentence with no puncatuation: > ")
sentence= sentence. lower()
keyword= input(" input a word from the sentence: > ")
keyword= keyword. lower()
words= sentence. split(' ')
for (i, subword) in enumerate(words):
if(subword == keyword):
print(i+1)
break
else:
print("error this word isnt in the sentence")