Unable to Get the Sum of Both Values

Question

I am doing some basic stuff with reading files, etc. I am tasked with finding how many lines (records) there are in the file and the total number of incidents (aggregation of one of the columns).

I have figured out both numbers, however, when I put all the code together, I get the sum of one of the criteria and total of 0 for the other. But when I do each criteria separately, I have no problems.

myFile = open("PS3_wnvhumancases.txt", "r")
nincidents = 0
for char in myFile.readlines():
    new_file = char.split(',')
    cases = new_file[-1]
    nincidents += int(cases)
nrecs = len(myFile.readlines())
print('Total Records Processed: ', nrecs)
print('Total Incidents: ', nincidents)
myFile.close()

The code above gives me the correct total of incidents and 0 for total reports

Meanwhile,

myFile = open("PS3_wnvhumancases.txt", "r")
nrecs = len(myFile.readlines())
print('Total Records processed: ', nrecs)
nincidents = 0
for char in myFile.readlines():
    new_splt = char.split(',')
    cases = new_splt[-1]
    nincidents += int(cases)
print('Total Incidents: ', nincidents)
myFile.close()

This block of code gives me the number of reports and 0 for total incidents.

Any suggestion that will give me both numbers?

This looks like it's because you are calling readlines twice, which will advance the pointer to the end of the file after the first time. Simply assign `myFile.readlines()` to a variable once and use that variable. — Ken Syme, Sep 23 '19 at 14:49
If you had tried to debug your program, you would have caught the reason before. — Austin, Sep 23 '19 at 14:50

score 1 · Answer 1 · answered Sep 23 '19 at 14:49

You are exhausting the file when you do .readlines(). You would need to seek back to start or just keep the output as a variable like below:

myFile = open("PS3_wnvhumancases.txt", "r")
content = myFile.readlines()
nrecs = len(content)
print('Total Records processed: ', nrecs)
nincidents = 0
for char in content:
    new_splt = char.split(',')
    cases = new_splt[-1]
    nincidents += int(cases)
print('Total Incidents: ', nincidents)
myFile.close()

Unable to Get the Sum of Both Values

1 Answers1