ramya natarajan wrote:
Hello,
I am very beginner to programming, I got task to Write a loop that
reads
each line of a file and counts the number of lines that are read until
the
total length of the lines is 1,000 characters. I have to read lines from
files exactly upto 1000 characters.
Here is my code:
I created file under /tmp/new.txt which has 100 lines and 2700
characters
, I wrote code will read exactly 1000 characters and count lines upto
those
characters.But the problem is its reading entire line and not stopping
excatly in 1000 characters. Can some one help what mistake i am doing
here?.
log = open('/tmp/new.txt','r')
lines,char = 0,0
for line in log.readlines():
while char < 1000 :
for ch in line :
char += len(ch)
lines += 1
print char , lines
1026 , 38 ---- Its counting entire line instead of character upto
1000
-- can some one point out what mistake am i doing here , where its not
stopping at 1000 . I am reading only char by car
My new.txt -- cotains content like
this is my new number\n
Can some one please help. I spent hours and hours to find issue but i
am not
able to figure out, Any help would be greatly appreciated.
Thank you
Ramya
The problem is ill-specified (contradictory). It'd probably be better
to give the exact wording of the assignment.
If you read each line of the file, then it would only be a coincidence
if you read exactly 1000 characters, as most likely one of those lines
will overlap the 1000 byte boundary.
But you have a serious bug in your code, that nobody in the first five
responses has addressed. That while loop will loop over the first line
repeatedly, till it reaches or exceeds 1000, regardless of the length of
subsequent lines. So it really just divides 1000 by the length of that
first line. Notice that the lines += 1 will execute multiple times for
a single iteration of the for loop.
Second, once 1000 is reached, the for loop does not quit. So it will
read the rest of the file, regardless of how big the file is. It just
stops adding to lines or char, since char reached 1000 on the first line.
The simplest change to your code which might accomplish what you want is
to put the whole thing inside a function, and return from the function
when the goal is reached. So instead of a while loop, you need some
form of if test. See if you can run with that. Remember that return
can return a tuple (pair of numbers).
There are plenty of other optimizations and approaches, but you'll learn
best by incrementally fixing what you already have.
DaveA
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