longestCommonPrefixWIP

#attempted a solution besides the one I resolved with guidance but I failed. Cannot seem to get the startswith method to work in the while loop. In other words, I tried to compare every character in one string to the other
#but I could not isolate the one with prefix. maybe later

class Solution:
    def longestCommonPrefix(self, myArr):
        prefix = myArr[0]
        print(prefix)
        myResult = ""
        nn = len(prefix)
        if myArr == "":
            return 
        #str1 = myArr[0]
        str2 = myArr[1]
        str3 = myArr[2]
        
        for i in str2[0:]:
            print(i)
            
            while i.startswith(nn(i)):
                print(prefix[:1])
                print(i.startswith(prefix[:1]))
                
                
               
                myResult += i
                #prefix = prefix[:1]
                nn += 1
            
        return prefix    
myVar = Solution()
myVar.longestCommonPrefix(["flower","flow","flight"])