Averaging Numbers From a Text file in python without using sum().

Question

Here is the question ( self teaching).
" Write a program that prompts for a file name, then opens that file and reads through the file, looking for lines of the form:

X-DSPAM-Confidence: 0.8475

Count these lines and extract the floating point values from each of the lines and compute the average of those values and produce an output as shown below. Do not use the sum() function or a variable named sum in your solution. "

I have had some help but I am not getting it. it was suggested to put the "continue" at the end of "if not" but I am not sure why. I also can't seem to sum the individual lines. I have extracted the numbers and added the counter but everything I have tried to sum then average fails.... There is nothing in the tutorials or the book that suggest how to even do this.

my code :

# Use the file name mbox-short.txt as the file name
fname = input("Enter file name: ")
fh = open(fname)
count = 0
for line in fh:
if not line.startswith("X-DSPAM-Confidence:") : continue
count = count + 1
numbers = line.find(':')
final = line[numbers+1:]
print(final)

So I added print(final) just to see if I have the numbers right. I get this.

0.8475

0.6178

0.6961

0.7565

0.7626

0.7556

0.7002

0.7615

0.7601

0.7605

0.6959

0.7606

0.7559

0.7605

0.6932

0.7558

0.6526

0.6948

0.6528

0.7002

0.7554

0.6956

0.6959

0.7556

0.9846

0.8509

0.9907

Please Help :(

Answer 1

@Aric What you did there wrong was you initialize ntot as an empty list *each time* in the loop. You have to do this before the loop begins.

Answer 2

@Aric You are getting in the right direction, as you have those numbers already! Now, instead of printing them, you might convert them to floats and add each of them to a variable. Then just divide this variable by counter and you have yourself the average without using sum() ;)

BTW, this sounds familiar... Are you perhaps doing Dr. Chuck's course on coursera.org? :)

Answer 3

@Aric Introduce a new variable called num. In the loop add a line:
num += float(final)

Outside the loop add:
print(num/counter)

Answer 4

No problem, man. Good luck with your course ;)

Answer 5

@Daniel BTW - By The Way ;)

Answer 6

Kuba what is BTW?

Answer 7

Before For add
finals=0

Try to add into for
finals+=line[numbers+1]

At the end
print((finals)/(numbers+1))

Answer 8

file= input("enter your filename:")
try:
filename = open(file)
readfile = filename.read()
except:
print("File is not found")
quit()
word = "X-DSPAM-Confidence:"
result=0
count = 0
for line in filename:
if line.startswith(word):
l = len(word)
number = float(line[l+1:])
result = result + number
count = count + 1
continue
try:
avg = result/count
except ZeroDivisionError:
avg =0
print("Average spam confidence:", avg)

Answer 9

Aric the best way to check how work your program or practice is printing values in different parts of your code. In this way you will see how it works and where do you must to do changes ;-)

Answer 10

Ok nevermind .. had to move print outside loop. thank you

the sad thing is I am not sure why what you all told me actually worked....

Answer 11

RIght I have converted to float now but I cant seem to get it to add each line.

yes it is coursera :)

I have been trying this but it wont sum.. just playing around with the sum even though it says not too.

fname = input("Enter file name: ")
fh = open(fname)
count = 0
for line in fh:
if not line.startswith("X-DSPAM-Confidence:") : continue
count = count + 1
numbers = line.find(':')
final = line[numbers+1:]
ntot = list()
ntot.append(float(final))
ftot = sum(ntot)
print(ftot)

Answer 12

To find average :
prompt = input("enter your filename:")
filename = open(prompt)
readfile = filename.read()
word = "X-DSPAM-Confidence:"
result = 0
count = 0
for line in readfile:
if line.startswith(word):
l = len(word)
number = float(line[l+1:])
result = result + number
count = count + 1
continue
avg = result/count
print(Average Spam Confidence:", avg)

Answer 13

fname = input("Enter file name: ")
fh = open(fname)
count = 0
sum = 0
for line in fh:
if line.startswith('X-DSPAM-Confidence:'):
count = count+1
num = float(line[line.find(":")+1:])
sum= sum+num

print('Average spam confidence:', sum / count)

Answer 14

Wont convert num += float(final)

nevermind figured it out.. TY !

well except it printed everything

0.8475
0.73265
0.7204666666666667
0.729475
0.7361
0.73935
0.7337571428571428
0.7372249999999999
0.7397666666666667
0.74184
0.7376636363636364
0.739575
0.7408307692307693
0.7422357142857143
0.7389666666666668
0.7400187500000002
0.7348764705882355
0.7326500000000001
0.7284473684210527
0.7270350000000001
0.7283857142857144
0.7268954545454547
0.7255478260869567
0.7268000000000002
0.7371120000000002
0.7414884615384617
0.7507185185185187