如何用「*」代替下列第一個字母的出現？

Question

我被困在這，我不知道該從這裏做什麼。

# returns a string that changes all occurrences of its first char have been changed to '*' 


def fix_start(str): 
    results = [] 
    str.startswith(str[1]) 
    results = 

例如：給定的字符串= '氣泡'，它應該返回：BU **樂

Answer 1

def fix_start(s): 
    return s[0]+ s[1:].replace(s[0],'*')