A simple Python 3 app to explore your Amazon.com purchase history CSV data.

amazon_purchase_analyzer.py

import csv
import sys
from collections import Counter, defaultdict
from datetime import datetime as dt
from decimal import Decimal
from time import sleep

# First import your purchases data from Amazon.com and store CSV
# file in the same directory as this program.
# Column names in CSV file for reference
# based on customer order download from Amazon.com as of 2/11/19.
# You can also print column names on CSV with print_csv_column_names().

# [1]  Order Date                [13] Shipping Address Zip
# [2]  Order ID                  [14] Order Status
# [3]  Payment Instrument Type   [15] Carrier Name & Tracking Number
# [4]  Website                   [16] Subtotal
# [5]  Purchase Order Number     [17] Shipping Charge
# [6]  Ordering Customer Email   [18] Tax Before Promotions
# [7]  Shipment Date             [19] Total Promotions
# [8]  Shipping Address Name     [20] Tax Charged
# [9]  Shipping Address Street 1 [21] Total Charged 
# [10] Shipping Address Street 2 [22] Buyer Name
# [11] Shipping Address City     [23] Group Name
# [12] Shipping Address State

def main():
    print_header()
    user_csv_file = input("\tEnter the name of your Amazon CSV file,\n"\
                      "\tthen press <enter>: ").strip()
    try:
        with open(user_csv_file, "r") as f:
            print()
            sleep(1) # impression of program crunching data, that's all
            print("\tSuccess!")
            sleep(1)
            print()
            run_event_loop(user_csv_file)
    except (FileNotFoundError, Exception) as e:
        print(f"\n\tUh, oh. There was a problem opening this CSV file:\n\n\t{e}",
              file=sys.stderr)
        print("\n\tPlease try again or enter a different CSV filename.\n",
              file=sys.stderr)
        main()

def run_event_loop(user_csv_file):
    """event loop asks user what they would like to do until quitting"""
    get_date_range_from_csv(user_csv_file)
    sleep(1)
    
    while True:
        print("\n\tChoose from the following options:\n")
        print("\t[1] Get total number of purchases")
        print("\t[2] Get total amount spent")
        print("\t[3] Get number of purchases per year")
        print("\t[4] Get purchases per month for a given year")
        print("\t[5] Get summary of package carriers")
        print("\t[6] Exit app\n")
        user_choice = input("\tWhat would you like to do? ").strip()
        print()

        # [1] Get total number of purchases
        if user_choice == "1":
            purchases = get_total_number_of_purchases(user_csv_file)
            print(f"\tHere are your total purchases on Amazon: {purchases}\n")
            print("-".center(79, "-"))
            sleep(2)

        # [2] Get total amount spent
        elif user_choice == "2":
            amount_spent = get_total_amount_spent(user_csv_file)
            print(f"\tYou spent a grand total of ${amount_spent}.\n")
            print("-".center(79, "-"))
            sleep(2)

        # [3] Get number of purchases per year
        elif user_choice == "3":
            purchases = get_purchases_per_year(user_csv_file)
            print("\tYou purchases per year are as follows:\n")
            for year, count in purchases.items():
                print(f"\t{year} = {count}")
            print()
            print("-".center(79, "-"))
            sleep(2)

        # [4] Get purchases per month for a given year
        elif user_choice == "4":
            user_year = int(input("\tWhat year would you like to query? "))
            purchases = get_purchases_per_month(user_csv_file, user_year)
            print(f"\n\tHere are your monthly number of purchases in {user_year}:\n")
            for month, count in purchases:
                print(f"\t{month:<10} {count}")
            print()
            print("-".center(79, "-"))
            sleep(2)

        # [5] Get summary of package carriers
        elif user_choice == "5":
            carriers = get_summary_of_carriers(user_csv_file)
            print("\tHere is your total package carrier summary:\n")
            for year, count in carriers.most_common():
                print(f"\t{year:<18} {count}")
            print()
            print("-".center(79, "-"))
            sleep(2)
            
        # Exit event loop
        elif user_choice == "6":
            print("\tThanks! Have a nice day.")
            break
            
        # Check for invalid input from user
        else:
            print("\tInvalid selection! Please choose from the following:\n",
                  file=sys.stderr)
            sleep(2)
            
def print_header():
    print("".center(79, "-"))
    print()
    print(" AMAZON PURCHASE HISTORY ANALYZER ".center(79))
    print()
    print("".center(79, "-"))
    print()

def get_date_range_from_csv(filename):
    """print purchase history range for user's csv file"""
    with open(filename, "r") as f:
        reader = csv.DictReader(f)
        order_dates = [row["Order Date"] for row in reader]
        start = order_dates[0]
        end = order_dates[-1]
    print(f"\tYour CSV file contains purchase history data for:\n")
    print(f"\t{start} through {end}")

def get_total_number_of_purchases(filename):
    """returns a count of total purchases from csv file"""
    with open(filename, "r") as f:
        reader = csv.reader(f)
        row_count = sum(1 for row in reader) - 1 # minus headings
    return row_count

def print_csv_column_names(filename):
    """function for user to print column names in csv file if needed"""
    with open(filename, "r") as f:
        reader = csv.DictReader(f)
        column_names = reader.fieldnames
    for idx, column in enumerate(column_names, 1):
        print(f"{[idx]}: {column}")

def get_total_amount_spent(filename):
    """returns total amount spent in csv file"""
    total = 0
    with open(filename, "r") as f:
        reader = csv.DictReader(f)
        for row in reader:
            # strip $ sign and occasional right whitespace
            amount = Decimal(row["Total Charged"][1:].rstrip())
            total += amount
    return "{:,}".format(total)

def get_purchases_per_year(filename):
    """asks user to enter a year and returns total number of purchases for that year"""
    buys_per_year = Counter()
    with open(filename, "r") as f:
        reader = csv.DictReader(f)
        for row in reader:
            year = row["Order Date"][-4:]
            buys_per_year[year] += 1
    return buys_per_year

def get_summary_of_carriers(filename):
    """returns a dict counter of carriers who have delivered packages.
    
    Counter's conveninent most_common() method is helpful for displaying
    sorted data, fyi."""
    carrier_names = Counter()
    with open(filename, "r") as f:
        reader = csv.DictReader(f)
        for row in reader:
            if row["Carrier Name & Tracking Number"]:
                items = row["Carrier Name & Tracking Number"].split("(")
                carrier = items[0]
                carrier_names[carrier] += 1
    return carrier_names

def get_purchases_per_month(filename, year):
    """gets buys per month for a given year as a tuple of (month, total buys)"""
    buys_per_month = defaultdict(int)

    with open(filename, "r") as f:
        reader = csv.DictReader(f)
        for row in reader:
            date = row["Order Date"].split("/") # ['4', '10', '2010']
            date_obj = dt(year=int(date[2]),
                          month=int(date[0]),
                          day=int(date[1]))
            month = date_obj.strftime("%B")
            if date_obj.year == year:
                buys_per_month[month] += 1

    months_list = ["January", "February", "March", "April",
                   "May", "June", "July", "August", "September",
                   "October", "November", "December"]
    sorted_monthly_buys = [(key, buys_per_month[key])
                           for key in months_list]
    return sorted_monthly_buys


if __name__ == "__main__":
    main()