Question

FUNCTIONS

In this assignment, you will revisit reading data from a file, and use that data as arguments (parameters) for a number of functions you will write.

You will need to:

1. Write and test a function square_each(nums)

   • Where nums is a (Python) list of numbers. It modifies the list nums by squaring each entry and replacing its original value. You must modify the parameter, a return will not be allowed!

2. Write and test a function sum_list(nums)

   • Where nums is a (Python) list of numbers. It returns the sum of the numbers in passed-in the list.

3. Write and test a function to_numbers(str_list)

   • Where str_list is a list of strings, each of which represents a number. Modify each entry in the list by converting it to a number. You can choose to use return the list, or just modify str_list in-place, similar to #1, above.

4. Write and test a function main()

   • Take the previous three functions and construct a main() function that will call these functions properly. The program computes the sum of the squares of numbers read from a file. Your program should prompt for a file name and print out the sum of the squares of the values in the file. Hint: use readlines()

You may download two example files of numbers to read in, numbers (space separated) or numbers (comma separated). You may choose to read in numbers in another format of your choosing, so long as you choose one method and document it in your program comments.

- make sure your program flexible enough to read in data that is separated by either -commas, or spaces.

Output¶

This example parses the numbers_csv.txt file. The result should be the same regardless of which input data was used.

This program computes the sum of the squares of numbers read from a file.
Please enter the file name: numbers_csv.txt
The sum of the squares of the numbers in the file is 32932.0

Answer 1

Thanks for the question, here is the code in Python. It would have been great if you would have shared the sample input files.

Nevertheless, I have made it flexible so it will work for both space and comma delimeters.

Hope it helps, thanks, let me know for any help with any other question.

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def square_each(nums):
    for i in range(len(nums)):
        nums[i] = nums[i] ** 2


def sum_list(nums):
    total=0
    for i in range(len(nums)):
        total+=nums[i]
    return total

def to_numbers(str_list):

    for i in range(len(str_list)):
        try:
            str_list[i] = float(str_list[i])
        except:
            pass



def main():
    filename = input('Please enter the file name: ')
  str_list=[]
    with open(filename,'r') as infile:
        for line in infile.readlines():
            if ',' in line:
                line = line.strip().split(',')
            else:
                line = line.strip().split()
            for val in line: str_list.append(val.strip())

    to_numbers(str_list)
    square_each(str_list)
    total = sum_list(str_list)
    print('The sum of the squares of the numbers in the file is {}'.format(total))

main()

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Code Screenshot

def square_each (nums): for i in range (len (nums)): nums[i] = nums[i] ** 2 def sum_list (nums): total=0 for i in range (len (nums)): total+=nums[i] return total def to_numbers (str_list): for i in range (len (str_list)): try: str_list[i] = float (str_list[i]) except: pass def main(): filename = input ("Please enter the file name: ") str_list=[] with open(filename, 'r') as infile: for line in infile. readlines (): if ',' in line: line = line.strip().split(',') else: line = line.strip().split() for val in line: str_list.append(val.strip()) to_numbers (str_list) square each (str list) total = sum_list (str_list) print ("The sum of the squares of the numbers in the file is {}'. format (total)) main()