I have written this code that does the job i want it to. What I want to do is figure out the big O notation for the code. So I want to learn how to calculate the time complexity and end up with a big O notation result. How is it done in lay mans terms?
"""
def treetocode(hTree):
    code = dict()
    
    def getCode(hNode, currentcode=""):
        if (hNode == None): return
        if (hNode.left == None and hNode.right == None):
            code[hNode.char] = currentcode
        getCode(hNode.left, currentcode + "0")
        getCode(hNode.right, currentcode + "1")
        if hNode.char == None:
            return None
        else:
            print('Character = {}  :  Freq = {} --- Huffman code {}'.format(hNode.char, hNode.freq, currentcode))
    getCode(hTree)
    return code
"""
 
    