Hi, I am working on a Python project. For the project, I have to read temperatures (average monthly temperatures from 2000-2018 in four cities) from a csv file, convert the temperatures from Celsius to Fahrenheit, and graph all the data on one graph. This is what I have so far: import csv import numpy as np import matplotlib.pyplot as plt def main(): open(data.csv, "r") Oslo =[] Harrisburg =[] Honolulu =[] Santiago =[] new_array=[] for year in range(2000,2018): for month in range(1,12): Oslo.append(value1) Harrisburg.append(value2) Honolulu.append(value3) Santaiago.append(value4) new_array.append(year) plt.plot(new_array, Oslo, 'b-', label = "Oslo") plt.plot(new_array, Harrisburg, 'r-', label = "Harrisburg") plt.plot(new_array, Honolulu, 'g-', label = "Honolulu") plt.plot(new_array, Santiago, 'y-', label = "Santiago") plt.legend(shadow = True, loc = "best") plt.xticks(np.arange(0, 216, 1.0)) plt.yticks(np.arange(min(temperature), max(temperature), 10.0)) plt.xlabel('Year') plt.ylabel('Temperature') plt.title("Average Monthly Temperature in Four Cities") plt.show() main() I think my main obstacle right now is how to open the csv file, because when I try to run the program, I get an error that says: "NameError: name 'data' is not defined". Any help is greatly appreciated. Thank you.