Python：ValueError：以10为底的int（）的无效文字：“”

Question

I'm creating code to get the average score in a CSV file.

CSV file looks like this:

5 Ser15

4 Ser15

3 Ser15

1st column are the scores, the second are the usernames.

This is my code so far:

   def av():
    with open("SciMedreport.csv","r") as f:
        average = 0
        Sum = 0
        row_count = 0
        for row in f:
            column = row.split(',')
            i=(int(column[0]))
            Sum += i
            row_count += 1
        average = Sum / row_count
        return 'The average is:', average
  av()

But this error appears...

  i=int(column[0])
ValueError: invalid literal for int() with base 10: '"'

When I print the whole row to check, this appears:

def av():
with open("SciMedreport.csv","r") as f:
    average = 0
    Sum = 0
    row_count = 0
    for row in f:
        print(row)
av()

This is the result:

5,Ser15
""

5,Ser15

""

4,Ser15

Anyone know of a way to fix this, or an alternative way to work out the average??

Answer 1

当您尝试用'，'分割行时，因为没有，整个字符串将被返回并且尝试将其转换为int（）给您错误，请尝试使用''

Answer 2

I am able to see a couple of errors in the code.

for row in f:
(1)    for column in row.split(','):
(2)            i=(int(column))
            Sum += i
        row_count += 1
(3)    average = Sum / len(column)

(1) When you split the row, what you get back is basically an array/list. In your case, it would be ['5', 'Ser15] . And instead of a for loop, you might want to change the code as follows:

for row in f:
    columns_list = row.split(',')
    i=(int(columns_list[0]))
    Sum += i
    row_count += 1
average = Sum / row_count

(2) Now you can't convert a list to an integer. What you might be interested in is i = int(column[0]) ie first number in the list ie first column of your CSV file.

(3) You want to find the average of all rows, right? Souldn't it be average = Sum / row_count ?

def av():
    with open("SciMedreport.csv","r") as f:
        average = 0
        Sum = 0
        row_count = 0
        divisor = 0
        for row in f:
            row_count += 1
            if row_count%2 == 0: # if it doesn't work, try changing to 1
                # print(row.split(','))
                divisor += 1
                # write rest of the code here, Sum += i etc.
                columns_list = row.split(',')
                i = int(columns_list[0])
                Sum += i
        average = Sum / divisor

Answer 3

def av():
    with open("SciMedreport.csv","r") as f:
        average = 0
        Sum = 0
        row_count = 0
        divisor = 0
        for row in f:
            row_count += 1
            if row_count%2 == 0: # if it doesn't work, try changing to 1
                # print(row.split(','))
                divisor += 1
                # write rest of the code here, Sum += i etc.
                columns_list = row.split(',')
                i = int(columns_list[0])
                Sum += i
        average = Sum / divisor

Thank you to user3903448!