题解 | #字符串排序#

stri = input()

alpa = [i for i in stri if i.isalpha()]  # 筛选字符

alpa = sorted(alpa,key=str.upper) # 将字符按照不区分大小进行排序
index = 0
for i in stri:
    if i.isalpha(): # 遍历源字符串，如果是字符就打印排序好的字符串
        print(alpa[index],end='')
        index += 1
    else:
        print(i, end='')
# print(alpa)
# print(alpa)