Python3.x键错误，已为'；dict'；大概

这些是我的代码，但当我尝试运行时，它会返回一个错误：

KeyError:'28'或其他带有数字的KeyError

但我想我已经把所有的数字都记在字典里了。。。 而且，数据[4:6]来自日期编号，例如20160407、20141105

def get_data_list(file_object,column_number):
    contents = []
    for string in file_object:
        contents.append(tuple(string.split(',')))
    list = []
    for i in range(len(contents) - 1):
        list.append((contents[i + 1][0], float(contents[i + 1][column_number])))
    list.sort()
    return list

def average_data(list_of_tuples):

    dict = {'01':'January','02':'Februday','03':'March','04':'April','05':'May','06':'June','07':'July','08':'August','09':'September','10':'October','11':'November','12':'December'}
    current_month = 0
    total = 0
    count = 1
    average_data = []
    for k in list_of_tuples:
        for data in k:
            data = str(data)
            month = data[4:6]
            if month == current_month:
                total += k[1]
                if count != 1:
                    count += 1
            else:
                current_month = month
                average = float(total/count)
                average_data.append((float(average),dict[data[4:6]]+data[0:4]))
                total = 0
        average_data = sorted(average_data)
    return average_data