Largest Number

def myfun(a,b):
    if a+b<b+a:
        return -1
    elif a+b>b+a:
        return 1
    else:
        return 0

class Solution:
    def largestNumber(self, nums: List[int]) -> str:
        nums=[str(i) for i in nums]
        nums.sort(reverse=True, key=cmp_to_key(myfun))
        ans=""
        for i in nums:
            if ans=="" and i=='0': #this is needed to remove the initial zeros
                continue
            ans+=i
        return ans if ans!="" else '0' #this is needed if input arr=['0','0']