secondMax3.py

def secondMax(nums):
        
        """
        :type num: List[string]
        
        """
        if len(nums) == 0:
            return -1
            
        fmax = float('-inf')
        for i in range(0,len(nums)):
            if fmax < float(nums[i]):
                fmax = float(nums[i])
        smax = float('-inf')
        flag = True
        for i in range(0,len(nums)):
            if float(nums[i]) < fmax and smax <= float(nums[i]):
                smax = float(nums[i])
                flag = False
        
        if flag:
           return -1
    
        return smax
        

#Example usage 
print(secondMax([1, float('-inf'),float('-inf')]))


assert secondMax([1, float('-inf'),float('-inf')])==float('-inf')
assert secondMax(['1.1','1.2','2.2','3.2','4.2']*3000)==3.2
assert secondMax(["1","2","3"])==2
assert secondMax(["3", "-2"])==-2
assert secondMax(["4", "4", "4"])==-1