What's wrong with this code?

Question

a="ass1.txt"
with open(a,"w")as f:
nn=int(input("enter no of elements :"))
for i in range(0,nn):
vv=input("enter element :")
if (i<nn-1):
f.write(vv)
f.write("\n")
else:
f.write(vv)
with open (a,"r")as f:
x=f.readlines()
x.sort()
print(x)
n=len(x)
print("Largest element is:",x[n-1])

Answer 1

You don't really need to distinguish between the last element and all other elements. You can just go

for i in range(0,nn):
vv=input("enter element :")
f.write(vv + '\n')

It doesn't make any difference that a line break will be appended to the last element.

I think your problem is that '\n' is part of each element and gets printed when you print the sorted items?

You can get rid of those by adding something like x = [e.strip() for e in x] after the readlines method.

Or use this instead:

with open (a,"r")as f:
x = [line.strip() for line in f.readlines()]

Answer 2

I see. That's because the numbers you enter are treated as strings and sorted lexicographically which means that they are sorted like words in a dictionary:

1
100
12
2
234
29

Here, the largest number would be 29 (which is obviously wrong).

To change that, convert the numbers to integers:

x = [int(e.strip()) for e in x]

Note that this will raise an exception if you enter strings that cannot be converted to integers.

Answer 3

Thank you so much mam for helping me, now the code working fine

New code :
a="ass1.txt"
with open(a,"w")as f:
nn=int(input("enter no of elements :"))
for i in range(0,nn):
vv=input("enter element :")
if (i<nn-1):
f.write(vv)
f.write("\n")
else:
f.write(vv)
with open (a,"r")as f:
v=f.readlines()
list1=[]
for i in v:
o=int(i)
list1.append(o)
list1.sort()
print(list1)
n=len(list1)
print("Largest element is:",list1[n-1])

Mam can you please give me some tips about how to write a good program with a proper structure.. And can u please give some idea about how can i reduce size of above code

Thank you!

Answer 4

The structure looks fine. You can make the code a little more compact like this:

a="ass1.txt"

with open(a, "w") as f:
nn = int(input("enter no of elements: "))
for i in range(nn):
vv = input("enter element: ")
f.write(vv + '\n')

with open (a, "r") as f:
x = sorted([int(line.strip()) for line in f])

print("Largest element is: ", x[-1])

Answer 5

By the way, you can open the file in w+ mode so you can both write to and read from the file without having to close it:

a="ass1.txt"
with open(a, "w+") as f:
nn=int(input("enter no of elements: "))
for i in range(nn):
vv=input("enter element: ")
f.write(vv + '\n')
f.seek(0) # jump back to the beginning of the file
x = sorted([int(line.strip()) for line in f])

print("Largest element is:",x[-1])

Answer 6

Thanks for your concern
But actually my problem is improper output
Can u please try this code once
Add some no's to list
And check if the output is the
Greatest no from the list

When i added elements as follows:
2345
123
556
234
564
It gave me output as 564 as the greatest no in list ☹️