Python - determine change in value fro one period to the next : Thanks in advance for your help.  I am new to Python (and coding in general), and am trying to do the several things, with the imported CSV file below.  The problem that I am having a problem is capturing (in a list) the change in revenue from one row to the next for example, the change in revenue from 10/18 to 11/18.  Ideally, I would have a final list with ["month", "change vs previous"].

Here is my existing code:

    import os
    
    import csv
    
    csvpath = os.path.join("C:/test2", "budget_data.csv")
    
    num_rows=0
    total_rev=0
    
    with open(csvpath, newline="") as csvfile:
        csvreader = csv.reader(csvfile, delimiter= ",")
        print(csvreader)
        csv_header =next(csvreader)
        print(f"CSV Header:  {csv_header}")
        for row in csvreader:
            num_rows=num_rows+1
            total_rev += int(row[1])
    
    
    print("")
    print("There are "+ str(num_rows) +" months of data!")
    print("Total Revenue is "+str(total_rev)+" dollars!")

