EMI Exercise Problem

Hello Folks,
I have created different functions for the exercise problem of EMI calculation but I am not getting how
to combine these all functions to get a single function to form a dictionary …
Can you guys please help me out?

def readlines(path):
    with open(path, 'r') as f:
        lines = f.readlines()
        return lines
def parse_values(data_line):
    result = []
    for item in data_line.strip().split(','):
        if item == '':
            result.append(0.00)
        else:
            result.append(float(item))
    return result
def list_of_parameter(parameters): # Parameter will be number like 1, 2, 3 to get list of amount, rate of intrest, down payment etc.
    lists = []
    for data_line in lines[1:]:
        values_in_data_line = parse_values(data_line)
        lists.append(values_in_data_line[parameters])           
    return lists
def all_list(no_of_column):
    final_list = []
    for i in range(0, no_of_column):
        single_list = list_of_parameter(i)
        final_list.append(single_list)
    return final_list
def parse_headers(header_line):
    return header_line.strip().split(',')