Question

2D Lists + File I/O

In a comma-separated input file named results.txt, you have been given the following information that records the weekly (movie) box office sales for 5 movies. A sample input file will include the following. The movie’s title is listed first, then its sales (in million dollars) for 7 days are listed.

Avengers,169.1,125.8,101.7,40.5,38.2,24.2,55.7 Shazam!,8.6,14.1,8.2,7.3,31.4,44.2,26.8 Breakthrough,14.8,16.1,18.0,18.9,19.8,21.8,24.6 The Best of Enemies,4.7,5.4,5.8,6.1,6.7,7.6,8.1 Dumbo,9.9,14.8,9.0,7.9,40.6,52.5,36.3

Write a complete Python program that includes code to do the following:

• read in the data from the results.txt file into a 2D list named results
• include a separate function named average that will calculate (and display to the screen) the average sales for each movie. (Your output should show the movie title and the amount. For example, Breakthrough’s average is $19.1 million)
• include a separate function named lowest that will calculate (and display to the screen) the lowest sales for each day.(Your output should show the day number and the amount. For example, Day 1’s lowest is $4.7 million)
• call the functions to execute within the “main” function

***Please be sure that any calculation results are printed showing one (1) decimal place.***

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

def main():
infile=open('results.txt','r')

movie=infile.readlines()

for x in range(len(movie)):
movie[x]= movie[x].rstrip('\n')
movie[x]= movie[x].split(',')

for row in range(len(movie)):
for col in range(1,len(movie[0])):
movie[row][col]=float(movie[row][col])

print(movie)
lowest(movie)
average(movie)
infile.close()

def lowest(movie):
for col in range(1,len(movie[0])):
smallest =movie[0][col]
for row in range(len(movie)):
if movie[row][col]<smallest:
smallest=movie[row][col]
print("Day",col,"'s lowest=$",format(smallest,'.2f'))
  
def average(movie):
for row in range(len(movie)):
total=0
for col in range(1,len(movie[0])):
total+=movies[row][col]
avg=total/(len( movie[0])-1)
print(movie[row][0],"'s average=$",format(avg,'.2f'))   

main()

This is the program I have written myself . I have listed the error below. any help?

Traceback (most recent call last):
File "/Users/user1/Downloads/StubbsLab5py.py", line 36, in <module>
main()
File "/Users/user1/Downloads/StubbsLab5py.py", line 13, in main
movie[row][col]=float(movie[row][col])
IndexError: list index out of range
>>>

Answer 1

your code worked fine. The problem is in the input file. The code will throw the particular error if you have extra empty lines after the text as shown in the first screenshot. So remove those extra lines and your code shall work fine.

# If you have a query/issue with respect to the answer, please drop a comment. I will surely try to address your query ASAP and resolve the issue

# # Please consider providing a thumbs up to this question if it helps you. by doing that, you will help other students who are facing a similar issue.

#------------------------FAULTY INPUT FILE---------------------

#----------------CORRECT INPUT FILE-----------------------------------------------

#----------------OUTPUT--------------------------

#-------------------------------------------------------

def main():

    infile=open('results.txt','r')

    movie=infile.readlines()

    # print(movie)

    for x in range(len(movie)):

        movie[x]= movie[x].rstrip('\n')

        movie[x]= movie[x].split(',')

    # print(movie)

    for row in range(len(movie)):

        for col in range(1,len(movie[0])):

            movie[row][col]=float(movie[row][col])

    # print(movie)

    lowest(movie)

    average(movie)

    infile.close()

def lowest(movie):

    for col in range(1,len(movie[0])):

        smallest =movie[0][col]

        for row in range(len(movie)):

            if movie[row][col]<smallest:

                smallest=movie[row][col]

        print("Day",col,"'s lowest=$",format(smallest,'.2f'))

def average(movie):

    for row in range(len(movie)):

        total=0

        for col in range(1,len(movie[0])):

            total+=movie[row][col]

            avg=total/(len( movie[0])-1)

        print(movie[row][0],"'s average=$",format(avg,'.2f'))

main()