How do I add a "else" clause to the loop for list "a"? if "inputString" has no character greater than the "keyChar", I am supposed to return a message to the user. Thank you much!

def char(keyChar, inputString): a = min([element for element in inputString.lower() if element > keyChar]); if a==[]: print ("No characters were larger than "+keyChar) #print(a); b= [pos for pos, char in enumerate(inputString) if char == a]; #print(b); print("In "+(inputString)+ ", the smallest character greater than "+(keyChar)+ " is "+a+ " and occurs at position "+str(b));