题解 | #字符串排序#

while True:
    try:
        s = input()
        s1 = ""
        for i in s:
            if i.isalpha():
                s1 += i
        l = sorted(s1, key=str.upper)  # 注意这个排序方法，upper后无()；等价于sorted(s1,key=lambda x: x.upper())
        n = 0
        s2 = ""
        for j in s:
            if j.isalpha():
                s2 += l[n]
                n += 1
            else:
                s2 += j
        print(s2)
    except:
        break