TypeError: '_io.TextIOWrapper' object is not subscriptable

Question

The main function that the code should do is to open a file and get the median. This is my code:

def medianStrat(lst):
    count = 0
    test = []
    for line in lst:
        test += line.split()
        for i in lst:
            count = count +1
            if count % 2 == 0:
                x = count//2
                y = lst[x]
                z = lst[x-1]
                median = (y + z)/2
                return median
            if count %2 == 1:
                x = (count-1)//2
                return lst[x]     # Where the problem persists

def main():
    lst = open(input("Input file name: "), "r")
    print(medianStrat(lst))

Here is the error I get:

Traceback (most recent call last):
  File "C:/Users/honte_000/PycharmProjects/Comp Sci/2015/2015/storelocation.py", line 30, in <module>
    main()
  File "C:/Users/honte_000/PycharmProjects/Comp Sci/2015/2015/storelocation.py", line 28, in main
    print(medianStrat(lst))
  File "C:/Users/honte_000/PycharmProjects/Comp Sci/2015/2015/storelocation.py", line 24, in medianStrat
    return lst[x]
TypeError: '_io.TextIOWrapper' object is not subscriptable

I know lst[x] is causing this problem but not too sure how to solve this one. So what could be the solution to this problem or what could be done instead to make the code work?

Answer 1

You can't index (__getitem__) a _io.TextIOWrapper object. What you can do is work with a list of lines. Try this in your code:

lst = open(input("Input file name: "), "r").readlines()

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Also, you aren't closing the file object, this would be better:

with open(input("Input file name: ", "r") as lst:
    print(medianStrat(lst.readlines()))

with ensures that file get closed.