如何按第一个字母对列表进行分组？

def group_by_first_letter(lst):
    groups = {}
    for item in lst:
        first_letter = item[0].upper()  # 假设列表中的元素都是字符串，并将首字母转为大写
        if first_letter not in groups:
            groups[first_letter] = []
        groups[first_letter].append(item)
    return groups

my_list = ["apple", "banana", "avocado", "orange", "pear", "pineapple"]
result = group_by_first_letter(my_list)
print(result)

{
  "A": ["apple", "avocado"],
  "B": ["banana"],
  "O": ["orange"],
  "P": ["pear", "pineapple"]
}