Question

***NEED SOLUTION IN PYTHON ***

1. Create a main function which only gets executed when the file is directly executed

Hint:

def main():
pass

if __name__ == '__main__':
main()

2. Your programs will use a file called scores.txt to store a bunch of user-provided numbers.
These can be int or float but their values must be between 0 and 100.

Inside the main function, display the current list of numbers to the user and ask if they want to update the list.

If currently no numbers are stored, display a message.

If the user wants to update the number list, provide them with options to do so. (Similar to how the movie programs adds or deletes movies)

Make sure to handle any possible exceptions in this step. Exceptions might occur if the user enters bad inputs or file is missing or cannot be read etc.

3. After they are done with the list of numbers, your program will display the following information about the list of numbers:

1. mean (or average)
2. mode
3. median
4. range

Write 4 different functions called mean, mode, median and range to get perform this task. Each of these functions will take in a list of numbers and return a number back except the range function which will return a tuple containing two numbers (min and max).

You can do a google search to find out the meanings of the 4 terms.

Do not use python's built-in functions to perform these tasks.

Make sure to write documentation and to perform exception handling in all four of these functions.

Answer 1

Below is the screenshot of the code. Comments are given explaining it.

Below are 2 outputs of the code:

1.

2.

Below is the code to copy:

#CODE STARTS HERE=======================

def range_of(li): #Finds min and max
   mini=float(li[0])
   maxii=float(li[0])
   for s in li:
      if float(s)<mini: #checks for smallest number
         mini = s
      if float(s)>float(maxii): #checkd for biggest number
         maxii = s
   ran = (mini,maxii) #creates tuple
   return ran

def median(li): #finds middle number in the list
   count =0
   for _ in li:
      count+=1
   if count % 2 == 0: #if length is even
      m1 = li[count // 2]
      m2 = li[count // 2 - 1]
      med = (m1+m2) / 2
   else: #if length is odd
      med = li[count // 2]
   return med

def mode(li): #finds most repeating number
   d = dict() #uses dictionary to store frequency
   for s in li:
      if s in d: #updates dict if number present
         d[s] += 1
      else: #creates new key if number is not present
         d[s] =1
   maxi = 0
   mod = 0
   for key,val in d.items(): #finding the greatest frequency
      if val>maxi:
         maxi=val
         mod = key
   return mod

def mean(li): #Finds average of list
   count =0
   sum_of=0
   for s in li:
      count+=1 #finds the length
      sum_of+= float(s) #finds total sum
   return sum_of/count

def main():
   with open("scores.txt",'r+') as f_r: #to display the existing values
      print("Below are the values in scores.txt")
      count =0
      for score in f_r:
         count+=1
         print(score, end="")
      if count == 0:
         print("    *The file is empty* \n")
      f_r.close()
   inp = input("Do you want to add scores?[y/n] ") #asking user for input
   scores_list = []
   scores_list_full = []
   if inp.strip().lower()== "y":
      print("Enter the numbers below. Enter 'q' to quit.")
      while True:
         try: #To catch any exceptions during value input by user
            s = input()
            if s.strip().lower() == "q":
               break
            if isinstance(s, (int, float)) or float(s)<0 or float(s)>100:
               raise Exception
            scores_list.append(s)
         except: #Prints error message and continues for next input
            print("Invalid Input")
            continue
   try: #To catch any exceptions while writing to the file
      with open("scores.txt","a+") as f:
         for score in scores_list:
            f.write(str(score)+"\n")
   except:
      print("Error in writing to the file")

   with open("scores.txt", 'r+') as f_r:
      for score in f_r:
         scores_list_full.append(float(score.strip())) #To store all values in the list for processing
   scores_list_full.sort()
   if len(scores_list_full)==0:
      exit()

   #function calls for processing the list of numbers
   mea = mean(scores_list_full)
   mod = mode(scores_list_full)
   med = median(scores_list_full)
   ran = range_of(scores_list_full)
   print("Mean :",mea,"\nMode :",mod,"\nMedian :",med,"\nran :",ran)

if __name__ == '__main__':
   main() #this is used to run only when the file is directly executed

#CODE ENDS HERE=========================