File size: 4,344 Bytes
e002dc4 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 |
"""
cli_demo.py
Author: Eugenia Tate
Date: August 24, 2025
A simple command-line application for a car dealership that allows users
to look up vehicle information (year, make, and model) by VIN number.
The app also lets a user view top 3 looked up vehicle makes.
The data is retrieved from the NHTSA (National Highway Traffic Safety
Administration) VIN decoding API via the helper module `nhtsa_api_call.py`.
Usage:
python cli_demo.py
"""
import nhtsa_api_call, re, csv, os
import pandas as pd
TOP3 = 3
def is_valid_vin (vin):
"""
Check whether vin is valid.
A valid VIN is a VIN of 17 alphanumeric characters long and can not
include I, O, Q.
"""
vin = vin.upper()
if len(vin) != 17:
return False
if not re.match(r'^[A-HJ-NPR-Z0-9]{17}$', vin):
return False
return True
def save_vehicle(year, make, model, filename = "vin_lookup_history.csv"):
"""Append VIN lookup result to a CSV file."""
file_exists = os.path.isfile(filename)
with open(filename, "a", newline="") as f:
writer = csv.writer(f)
if not file_exists:
# add first row
writer.writerow(["year", "make", "model"])
writer.writerow([year, make, model])
def display_top3(filename = "vin_lookup_history.csv"):
"""Show top 3 car makes by lookup frequency"""
# if file does not exist then there is no history yet
if not os.path.isfile(filename):
print("\nNo VIN lookup history found. Please look up some VINs first.\n")
return
# create a dataframe using file data
df = pd.read_csv(filename)
# save number each make appears in the log as a series
counts = df['make'].value_counts()
# file exists but no data has been added yet
if len(counts) == 0:
print("\n No data in the log yet.\n")
return
# if there are fewer than 3 data entries in the log then the program will
# at least display 1 or 2 most looked up makes
if len(counts) < TOP3:
print(f"\nNot enough data for displaying top 3. Showing top {len(counts)} instead:\n")
top_makes = counts.head(len(counts))
else:
print(f"\n Top {TOP3} Car Makes from Lookups:\n")
top_makes = counts.head(TOP3)
for make, count in top_makes.items():
print(f" {make}: {count} lookups")
# an empty line print to space out CLI prompts
print()
def main():
"""
Run the command-line VIN lookup loop.
Prompts the user for a VIN number, calls the NHTSA API,
and prints out the vehicle information if found.
Enter '0' to exit.
"""
print("🚗 Welcome to the Car Dealership VIN Lookup!\n")
while True:
print("Choose an option from the menu:")
print("1. Lookup a VIN")
print("2. Show Top 3 Most Looked-up Makes")
print("0. Exit")
choice = input("Enter your choice: ").strip()
# exit condition gets checked first
if choice == "0":
print("👋 You chose to exit VIN lookup. Goodbye!")
break
# user selected to add a VIN
elif choice == "1":
vin = input("Please enter a valid VIN or 0 (zero) to exit: \n").strip()
if vin == "0":
continue
# check if vin is valid, and if not print error message
if not is_valid_vin(vin):
print("Invalid VIN format. Must be 17 letters/numbers (no I, O, Q). Try again.\n")
continue
# vin is valid, perform VIN lookup
else:
year, make, model = nhtsa_api_call.get_vehicle_info(vin)
if year and make and model:
print(f"✅ VIN {vin}")
print(f" Year: {year}")
print(f" Make: {make}")
print(f" Model: {model}")
save_vehicle(year, make, model) #save the data in the lookup history file
else:
print(f"❌ VIN {vin} not found in database. Try again.")
# user selected to view top3 vehicle makes
elif choice == "2":
display_top3()
# user entered something other than 1,2 or 0
else:
print("Invalid option. Please choose 1, 2, or 0.\n")
if __name__ == "__main__":
main()
|