Question

23.4 PROJECT 4: Using Pandas for data analysis and practice with error handling

Overview

In this project, you will use the Pandas module to analyze some data about some 20th century car models, country of origin, miles per gallon, model year, etc.

Provided Input Files

An input file with nearly 200 rows of data about automobiles. The input file has the following format (the same as what you had for your chapter 13 labs). The following is an example of some of the lines in the file:

mpg,cylinders,displacement,horsepower,weight,acceleration,model_year,origin,name
18,8,307,130,3504,12,70,usa,chevrolet chevelle malibu
15,8,350,165,3693,11.5,70,usa,buick skylark 320
18,8,318,150,3436,11,70,usa,plymouth satellite
16,8,304,150,3433,12,70,usa,amc rebel sst

Description

The first thing your program will need to do is prompt the user for a csv file name. Your prompt must be exactly Enter the filename:You will then read that csv file into a dataframe, and use that data in your analysis. If the file can not be opened, your program should not crash, but should print out the message Can't open file. Exiting program. and then exit the program.

You will use a menu, like in the last project, and call several functions according to the user's menu selection.

You program should have a menu exactly as follows (the menu always prints a blank line first):

(1) Get max mpg model
(2) Get min mpg model
(3) Get model year range
(4) Exit

Enter selection 1-4:

If the user enters an invalid menu selection (including a non-numeric input, or a number outside of the valid range), your program should not crash, but should print the message Invalid selection - must be a number from 1 to 4, then display the menu again. For each menu selection other than Exit, you will first prompt the user for a country of origin. The prompt should be exactly Enter the country of origin: (with a space following the colon). The countries that are in the file are "usa", "japan", and "europe". Then you will call a function for each menu selection and country that was input. If the user enters an unexpected input for the country, you should output the message Invalid country and then display the entire menu again, including the beginning blank line (you do not need to remember which menu item they selected).

An example of what output should look like for a sample of various inputs follows this description.

You will need to use the following functions:

• def get_max_mpg_model(carsdataframe, country) - this function will accept as parameters a dataframe of data, with the same columns as the original file, and a country, which is a string. The function should return a string which is the name of the car model from the country indicated that has the maximum mpg of all models from that country. For example, if the user selected menu item 1 and then input 'usa', the get_max_mpg_model function will be passed a data frame and the string 'usa'. It will return the string 'chevrolet chevette', since the chevrolet chevette is the model name with the best mpg among those models in the data whose country of origin is the usa. Upon return from the function with the above parameters, the following message should be printed: Best mpg model from usa is chevrolet chevette

• def get_min_mpg_model(carsdataframe, country) - this function is the same as the get_max_mpg_model function, but will return the model name with the minimum mpg for the indicated country. The message printed upon return from the function would be something like Worst mpg model from usa is chevrolet chevette

• def get_model_year_range(carsdataframe, country) - this function will take as parameters a dataframe and a country, like the other two, but this function will return two values, the minimum model year and the maximum model year for the indicated country. The message printed upon return from this function is, as an example Model years range from 1970 to 1975. Note that when the data is read into the data frame, the years are two digit integers. You will have to change them to strings in order to output the correct message.

• Your code will be cleaner and much easier if you create a function that prints the menu.

In the main program, you should open the input file using the pandas read_csv() method and read the contents of the file into a DataFrame. Then display the menu to see what the user wants to do, and perform the function as indicated by the user.

Once the selected menu function has returned, the main program should print out the best (max) mpg model, the worst (min) mpg model, or the model year range according to the selected function, as follows:

Example: If the user inputs the following, in order:

mpg.csv
1
usa
3
japan
2
europe
4

the console will look like this:

Enter the filename:mpg.csv

(1) Get max mpg model
(2) Get min mpg model
(3) Get model year range
(4) Exit

Enter selection 1-4:1

Enter the country of origin: usa
Best mpg model from usa is: chevrolet chevette

(1) Get max mpg model
(2) Get min mpg model
(3) Get model year range
(4) Exit

Enter selection 1-4:3

Enter the country of origin: japan
Model years range from 1970 to 1975

(1) Get max mpg model
(2) Get min mpg model
(3) Get model year range
(4) Exit

Enter selection 1-4:2

Enter the country of origin: europe
Worst mpg model from europe is: volvo 145e (sw)

(1) Get max mpg model
(2) Get min mpg model
(3) Get model year range
(4) Exit

Enter selection 1-4:4

If the user inputs a bogus file name, the output should look like this:

Enter the filename:bogusfilename
Can't open file.  Exiting program.

If the user inputs an invalid menu choice, like -3 or end, the output should look like this:

Enter the filename:mpg.csv

(1) Get max mpg model
(2) Get min mpg model
(3) Get model year range
(4) Exit

Enter selection 1-4:-3
Invalid selection - must be a number from 1 to 4

(1) Get max mpg model
(2) Get min mpg model
(3) Get model year range
(4) Exit

Enter selection 1-4:end
Invalid selection - must be a number from 1 to 4

(1) Get max mpg model
(2) Get min mpg model
(3) Get model year range
(4) Exit

Enter selection 1-4:4

If the user inputs an invalid country, such as australia, the output should look like this:

Enter the filename:mpg.csv

(1) Get max mpg model
(2) Get min mpg model
(3) Get model year range
(4) Exit

Enter selection 1-4:1

Enter the country of origin: australia
Invalid country

(1) Get max mpg model
(2) Get min mpg model
(3) Get model year range
(4) Exit

Enter selection 1-4:4

NOTE: The interactive terminal in zyBooks does NOT work with data frames. This means you MUST use Spyder or some other environment to develop your project, then once it is working, you can paste it into zyBooks for testing. Remember that your output and your prompts need to be EXACTLY as shown in the specifications in order to pass the tests.

Second Note: mpg.csv is available to download. If you pass the first test, but can not pass the other ones, it is likely because you hard coded something about the data from the mpg.csv file. Your program needs to work no matter what other file is tested. You will not be able to see the other test file. If your program is working properly for the mpg.csv file, it will work properly for the other file as well.

Answer 1

ANSWER:

Below i am providing the screen shots to this code along with output.

In get_max_mpg_model i have used a for loop with a condition to copy all mpg values of a particular country.

and in get_model_year_rang i am returning a tuple value which is unwrapped in calling function.

Editor - C:\Users\sookshmas\Desktop\sample_projects cars.py cars.py 1 import pandas as pd 3 def unique(listi): # intilize a null List unique_list = [] 11 # traverse for all elements for x in listi: # check if exists in unique_List or not if x not in unique_list: unique_list.append(x) return unique_list 14 def get_max_mpg_model(carsdataframe, country): res=[carsdataframe["mpg"][idx] for idx,t in enumerate(carsdataframe["origin"]) if t == country] 15 16 17 return max(res) 25 20 def get_min_mpg_model(carsdataframe, country): res=[carsdataframe["mpg"][idx] for idx,t in enumerate(carsdataframe["origin"]) if t == country] 22 return min(res) 23 24 def get_model_yrar_range (carsdataframe, country): res=[carsdataframe["model_year"][idx] for idx,t in enumerate(carsdataframe["origin"]) if t == country] 26 return (min(res), max(res)) 27 28 def main(): print("Enter the filename: ") filename=input() try: carsdata=pd.read_csv(filename) countries=unique(carsdata["origin"]) choice=0 while(choice!=4): print("(1) Get max mpg model\n") print("(2) Get min mpg model\n") nrint/"/31 Get model verrannoin"

cars.py ® print("(4) Exit\n\n\n") print("Enter selection 1-4: ") try: choice-int(input()) if choice==4: break except ValueError: print("Invalid selection - must be a number from 1 to 4\n") choice=0 continue if choice!=0: print("\nEnter the country of origin:") c=input() if not c in countries: print("\n Invalid country\n") choice=0 if choice==0: pass elif choice==1: res-get_max_mpg_model(carsdata,c) print("\nBest mpg model from "+str(c)+" is: "+str(res)+" \n") elif choice==2: res-get_min_mpg_model(carsdata, c) print("InWorst mpg model from "+str(c)+" is: "+str(res)+" \n") elif choice==3: fr, to-get_model_yrar_range(carsdata,c) print("\nModel years range from "+str(fr)+" to "+str(to)+" \n") elif choice > 4: print("Invalid selection - must be a number from 1 to 4\n") choice=0 except OSError as e: print(e) print("Can't open file. Exiting program") 73 74 if _name__ =="_main__": 75 main() 76

1 mpg, cylinders, displacement, horsepower, weight, acceleration, model year, origin, name 2 18,8,307,130,3504,12, 2001, usa, chevelle malibu 3 15,8,350, 165,3693, 11.5, 2002, usa, buick skylark 320 4 18,8,318, 150, 3436,11, 2006, usa, plymouth satellite 5 16,8,304,150, 3433, 12, 2012, usa, amc rebel sst 6 23,5,344, 134,3033, 12, 2006, europe, amc rebel sst

IPython console a Console 1/A Python 3.7.5 (default, Oct 31 2019, 15:18:51) [MSC v.1916 64 bit (AMD64)] Type "copyright", "credits" or "license" for more information. IPython 7.9.0 -- An enhanced Interactive Python. Restarting kernel... In [1]: runfile('C:/Users/sookshmas/Desktop/sample_projects/cars.py', wdir='C:/Users/sookshmas/Desktop/sample_projects') Enter the filename: mpg [Errno 2] File b'mpg' does not exist: b'mpg' CAn't open file. Exiting program In [2]: runfile('C:/Users/ sookshmas/Desktop/sample_projects/cars.py', wdir='C:/Users/ sookshmas/Desktop/sample_projects') Enter the filename: mpg.csv (1) Get max mpg model (2) Get min mpg model (3) Get model year range (4) Exit Enter selection 1-4: Enter the country of origin: usa Best mpg model from usa is: 18 (1) Get max mpg model 12) Get min mno model

IPython console Console 1/A (1) Get max mpg model (2) Get min mpg model (3) Get model year range (4) Exit Enter selection 1-4: Enter the country of origin: usa Worst mpg model from usa is: 15 (1) Get max mpg model (2) Get min mpg model (3) Get model year range (4) Exit Enter selection 1-4: Enter the country of origin: usa Model years range from 2001 to 2012 (1) Get max mpg model LO. Get min mne model

IPython console Console 1/ usa Model years range from 2001 to 2012 (1) Get max mpg model (2) Get min mpg model (3) Get model year range (4) Exit Enter selection 1-4: Invalid selection - must be a number from 1 to 4 (1) Get max mpg model (2) Get min mpg model (3) Get model year range (4) Exit Enter selection 1-4: Enter the country of origin: germany Invalid country (1) Get max mpg model (2) Get min mpg model

IPython console Console 1/ usa Model years range from 2001 to 2012 (1) Get max mpg model (2) Get min mpg model (3) Get model year range (4) Exit Enter selection 1-4: Invalid selection - must be a number from 1 to 4 (1) Get max mpg model (2) Get min mpg model (3) Get model year range (4) Exit Enter selection 1-4: Enter the country of origin: germany Invalid country (1) Get max mpg model (2) Get min mpg model

IPython console Console 1/13 Enter the country of origin: germany Invalid country (1) Get max mpg model (2) Get min mpg model (3) Get model year range (4) Exit Enter selection 1-4: Enter the country of origin: usa Best mpg model from usa is: 18 (1) Get max mpg model (2) Get min mpg model (3) Get model year range (4) Exit Enter selection 1-4: In [3]:

This is the complete code for this project please refer the above screenshots for indentation.

import pandas as pd

def unique(list1):
  
# intilize a null list
unique_list = []
  
# traverse for all elements
for x in list1:
# check if exists in unique_list or not
if x not in unique_list:
unique_list.append(x)
return unique_list
def get_max_mpg_model(carsdataframe, country):
res=[carsdataframe["mpg"][idx] for idx,t in enumerate(carsdataframe["origin"]) if t == country]
  
return max(res)
  
  
def get_min_mpg_model(carsdataframe, country):
res=[carsdataframe["mpg"][idx] for idx,t in enumerate(carsdataframe["origin"]) if t == country]
return min(res)
  
def get_model_yrar_range(carsdataframe,country):
res=[carsdataframe["model_year"][idx] for idx,t in enumerate(carsdataframe["origin"]) if t == country]
return (min(res),max(res))

def main():
print("Enter the filename: ")
filename=input()
try:
carsdata=pd.read_csv(filename)
countries=unique(carsdata["origin"])
choice=0
while(choice!=4):
print("(1) Get max mpg model\n")
print("(2) Get min mpg model\n")
print("(3) Get model year range\n")
print("(4) Exit\n\n\n")
print("Enter selection 1-4: ")
try:
choice=int(input())
if choice==4:
break
except ValueError:
print("Invalid selection - must be a number from 1 to 4\n")
choice=0
continue
  
if choice!=0:
print("\nEnter the country of origin: " )
c=input()
if not c in countries:
print("\n Invalid country\n")
choice=0
if choice==0:
pass
elif choice==1:
res=get_max_mpg_model(carsdata,c)
print("\nBest mpg model from "+str(c)+" is: "+str(res)+" \n")
elif choice==2:
res=get_min_mpg_model(carsdata,c)
print("\nWorst mpg model from "+str(c)+" is: "+str(res)+" \n")
elif choice==3:
fr,to=get_model_yrar_range(carsdata,c)
print("\nModel years range from "+str(fr)+" to "+str(to)+" \n")
elif choice > 4:
print("Invalid selection - must be a number from 1 to 4\n")
choice=0
except OSError as e:
print(e)
print("CAn't open file. Exiting program")
  
if _name_ =="_main_":
main()