Upper case only on specific characters in python string/list

Question

I am learning python list and string functions. I need to write a specific function. My function returns correctly the Else task. However, I am not able to capitalize only the first and last letter of each word in the given sentence. Thank you for your help, I can only use basic functions as given in the hints.

Here is the task: If the given sentence starts with *, capitalizes the first and last letters of each word in the sentence, and returns the sentence without *. Else, joins all the words in the given sentence, separating them with a comma, and returns the result.

For example if we call capitalize_or_join_words("*i love python"), we'll get "I LovE PythoN" in return. If we call capitalize_or_join_words("i love python"), we'll get "i,love,python" in return. If we call capitalize_or_join_words("i love python "), we'll get "i,love,python" in return.

Hints: The startswith() function checks whether a string starts with a particular character. The capitalize() function capitalizes the first letter of a string.The upper() function converts all lowercase characters in a string to uppercase. The join() function creates a single string from a list of multiple strings

def capitalize_or_join_words(sentence):

if sentence.startswith('*'):
    s = sentence.replace('*','')
    s2 = s.split()
    
    s3 = []

    for word in s2:
        s3 += word.capitalize()
    
    temp = ",".join(s3)
    sentence_revised = temp
    
else:
    
    s = sentence.split()
    sentence_revised = ",".join(s)

return sentence_revised

Answer 1

Here is what I came up with:

def capitalize_word(word):
    if not word:
        return ''
    if len(word) < 3:
        return word.upper()
    return word[0].capitalize() + word[1:-1] + word[-1].capitalize()

def capitalize_or_join_words(sentence):
    if sentence.startswith('*'):
        words = sentence.replace('*', '').split()
        return ' '.join(capitalize_word(word) for word in words)

    words = sentence.split()
    return ','.join(words)