Re: [Tutor] Help required to count no of lines that are until 1000 characters
Dave Angel da...@ieee.org wrote 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. Oooh, good catch, I completely missed that one! :-) Alan G ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] Help required to count no of lines that are until 1000 characters
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
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Re: [Tutor] Help required to count no of lines that are until 1000 characters
On Tue, May 11, 2010 at 1:00 PM, ramya natarajan nramy...@gmail.com wrote:
Hello, I have to read lines from
files exactly upto 1000 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
here's the pseudocode of what you're doing, it might help you
understand what the problem is:
for every line in the file:
if the character count is less than 1000, add the length of the
current line.
You are missing a condition.
Here is another version of your code that has the same problem, see if
this helps make it clearer:
lines, chars = 0,0
with open('/temp/new.txt') as f:
for line in f:
if chars 1000: break
chars += len(line)
This sounds a lot like a homework problem so I won't give you the
answer, but I hope that helps.
Also do you realize you are counting newlines as well? You may not
want to do this, depending on your intended application.
Hope that helps,
-Luke
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Re: [Tutor] Help required to count no of lines that are until 1000 characters
On Tue, 11 May 2010 11:00:20 -0700
ramya natarajan nramy...@gmail.com 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
Either you read line per line, but then you cannot stop exactly at the 1000th
character; or you traverse the text char per char, but this is a bit picky.
I would read line per line, and when count = 1000, read chars inside current
line to get to the 1000th, if needed.
(Your specification does not state this, but your disappointment seems to be
about that issue ;-)
Denis
vit esse estrany ☣
spir.wikidot.com
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Re: [Tutor] Help required to count no of lines that are until 1000 characters
On 12-May-2010, at 12:32 AM, spir ☣ wrote:
On Tue, 11 May 2010 11:00:20 -0700
ramya natarajan nramy...@gmail.com 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
Either you read line per line, but then you cannot stop exactly at the 1000th
character; or you traverse the text char per char, but this is a bit picky.
I would read line per line, and when count = 1000, read chars inside current
line to get to the 1000th, if needed.
(Your specification does not state this, but your disappointment seems to be
about that issue ;-)
Denis
You can try read instead of readlines.
Something like...
print 'Number of lines till 1000th character:',
len(open('/tmp/new.txt','r').read(1000).split('\n'))
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Re: [Tutor] Help required to count no of lines that are until 1000 characters
spir ☣ denis.s...@gmail.com wrote Either you read line per line, but then you cannot stop exactly at the 1000th character; or you traverse the text char per char, but this is a bit picky. Or you could just read 1000 chars from the file then pick out the lines from that. But that requires you to count newlines as characters! :-) HTH, Alan G. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Help required to count no of lines that are until 1000 characters
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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