Question

I’m trying to implement a program that computes the sum of the squares of numbers read from a file.

The numbers in the .txt file are:

37
42
59
14
25
95
6

So far I have:

def squareEach(nums):
    nums = nums * nums

def sumList(nums):
    nums = nums + nums

def toNumbers(strList):
    while line != "":
            line = int(line)
            line = infile.readline()

def main():
    print "** Program to find sum of squares from numbers in a file **"
    fileName = raw_input("What file are the numbers in?")
    infile = open(fileName, 'r')
    line = infile.readline()
    toNumbers(line)
    squareEach(line)
    sumList(line)
    print sum

When I run the program through I get:

main()
** Program to find sum of squares from numbers in a file **
What file are the numbers in?C:\Users\lablogin\Desktop\mytextfile.txt

Traceback (most recent call last):
File "<pyshell#17>", line 1, in <module>
main()
File "<pyshell#16>", line 6, in main
toNumbers(strList)
NameError: global name 'strList' is not defined

Answer 1

Normally, I would include a much more detailed explanation, but since I have to run, I’ll leave you with an amended version of your code that will work

def squareEach(nums):
    answer = []
    for num in nums:
        answer.append(num*num)
    return answer

def sumList(nums):
    answer = 0
    for num in nums:
        answer += num
    return answer

def toNumbers(strList):
    answer = []
    for numStr in strList.split():
        try:
            num = int(numStr)
            answer.append(num)
        except:
            pass
    return answer

def main():
    print "** Program to find sum of squares from numbers in a file **"
    fileName = raw_input("What file are the numbers in? ")
    sum = 0
    with open(fileName, 'r') as infile:
        for line in infile:
            nums = toNumbers(line)
            squares = squareEach(nums)
            sum += sumList(squares)
        print sum

Of course, you could do all of it in one line:

print "the sum is", sum(int(num)**2 for line in open(raw_input("What file are the numbers in? ")) for num in line.strip()split())

Hope this helps