[pythonvis] Re: Short projet

  • From: "Jim Snowbarger" <snowman@xxxxxxxxxxxxxxxx>
  • To: <pythonvis@xxxxxxxxxxxxx>
  • Date: Wed, 3 Jun 2015 12:33:17 -0500

Thank you for this. As near as I can tell, this meets the original
requirements.

You were seeking feedback, so here are a few personal observations, many just a
matter of opinion and preference. But, for what it’s worth…



I learned a few things from this. I didn’t realize that putting a comma after
the print statement would prevent moving to the next line, but would instead
insert a space, and stay on the same line. So, the space separation seems to
be provided simply by the fact that python is inserting a space on it’s own.
Is that right?

It works, but seems a little less desireable, and less than explicit, to have
the code depend on an obscure behavior like that.

And, I was surprised by the printing of the backspace to retract a character.
I didn’t realize it would do that. That is a little messy, even though it
apparently works. It would be better behaved code if it didn’t employ this
method to correct for itself. That is, in general, it is better for code to
always do the right thing, than it is for it to knowingly do the wrong thing,
however temporarily, and then take a step to correct for it.

But, I’m sure you already knew that.



Yep, I think you could condense that to one loop pretty easily, since both
loops have the same conditional, except that the inner loop is routinely
escaped using the break statement.

Usually, people will use something like break to handle some strange exception,
not typical behavior.

This works correctly, but, as you say, could be refined.



In reading this code, there are cases where two blocks end at the same point.
So, you will see two outdents. This code does it correctly. But, I sometimes
find it a little disconcerting to keep track of.



Sighted people probably love you for indenting 4 spaces. Being a braille user,
I prefer two. But, using 4 has the unintended consequence of discouraging
deep nesting. People often say that, if your functions are deeply nested, it
is a sign that the function should be decomposed, and broken into multiple
functions to handle some of the inner portions of the logic.

That problem doesn’t necessarily pertain to this code.

But, even so, since statements are still running off the end of the display, I
still lean toward 2 spaces. Just my personal opinion about that.



I have attached an edited version of this code, where I show a technique that I
use to keep myself straight. By inserting, #endif, or something similar, I
remind myself that this isn’t an indentation mistake, but was intentional.

It’s just a habit of my own that I offer in case you find it useful.

It sure helps me keep track of things.



I did not edit it for this, but I also am getting in the habit of putting a
comment block at the start of each function, to clearly describe the inputs and
the returned values.

You can figure all that out by reading the code. But, the intent of the
comment is to prevent you from having to slog through it all , just to figure
out how to use it.

Usually, that takes the form of a couple lines,

#inputs: list and briefly describe each input, one per line.

#returns: list and briefly describe each returned value, one per line.

Maybe this should be enclosed in the triple quotes, so it can be learned with
the help statement.

DocString?



Anyway, thanks very much for this. It seems to be functionally correct.



But, in recognition of the fact that most problems have an infinite number of
solutions, which makes me feel better in light of the apparent fact that some
probmes have no solution at all, it would be interesting to be able to score a
solution not just on whether it meets an input/output requirement, but on it’s
efficiency as well.

In general, my priorities would be:

1. Proper behavior

2. Readability and maintainability.

3. Efficiency.



So, does anybody know right off the top how to acquire high-resolution time
from the operating system? It would be cool to be able to stress test various
solutions, and see how long each takes.











From: pythonvis-bounce@xxxxxxxxxxxxx [mailto:pythonvis-bounce@xxxxxxxxxxxxx] On
Behalf Of Dzhovani
Sent: Wednesday, June 03, 2015 12:35 AM
To: pythonvis@xxxxxxxxxxxxx
Subject: [pythonvis] Re: Short projet



Hi,
I'm not sure that it is the best solution, so any critisism will be highly
appreciated. The code is attached, but I'm pasting it below as well:

def presentNums(seq):
seq.reverse() # reverse the list for faster pop operation later

while len(seq) > 0:
line = [] # creates the line to be printed and sets it to be empty at
the beginning of the iterate
length = 0 # the supposed length of the printed line
prolong =0 # prolong will be a variable to hold how longer the line
will become. it adds one for the space in between
while len(seq) > 0:
if seq[-1] < 10:
prolong = 2
elif seq[-1] < 100:
prolong = 3
else:
prolong = 4
length += prolong
if length <= 33:
line.append(seq.pop())
else:
break # leaves the inner loop
for each in line:
print each,
print "\b" # after the line is printed, it removes the last space from
the line

seq = [1, 2, 3, 4, 56, 76, 100, 99, 56, 29, 82,93, 74, 48, 95, 43, 25, 36, 71,
100, 100, 100, 100, 13, 100,37, 86, 100, 100]
print "start function"
presentNums(seq)

On 2.6.2015 г. 17:33 ч., derek riemer wrote:

Oddly enough, I needed a variant this function that splits a 1 dimentional
string into a 2 dimentional array of row length 10 yesterday and wrote it. but
I will hold off posting it in case anyone wishes to write it.

On 5/31/2015 7:58 PM, Jim Snowbarger wrote:

Anybody want to take a crack at this one?



Write a function that takes a list, of indefinite size. The list elements
consist of numbers, in the range of 1 to 100, but you have no idea how many
list elements there will be. Typical list But, as a sample, lengths might be
50 elements at most.

Process the list, and print the output in a series of lines that do not exceed
32 characters each.



Numbers on each line should be separated by a single space, and a number should
not span multiple lines.

Because the numbers are in the range of 1 through 100, some numbers take fewer
spaces than others, That is, the number 1 should be written as “1” not “001” ,
nor be space padded, such as “ 1”. Think of packing numbers together in the
interests of conserving braille display real estate.



If anybody takes it on, let me know.

















_____


<http://www.avast.com/>

В писмото няма вируси или малуер, защото avast! Антивирус
<http://www.avast.com/> защитата е активна.



JPEG image

def presentNums(seq):
seq.reverse() # reverse the list for faster pop operation later

while len(seq) > 0:
line = [] # creates the line to be printed and sets it to be empty at
the beginning of the iterate
length = 0 # the supposed length of the printed line
prolong =0 # prolong will be a variable to hold how longer the line
will become. it adds one for the space in between
while len(seq) > 0:
if seq[-1] < 10:
prolong = 2
elif seq[-1] < 100:
prolong = 3
else:
prolong = 4
length += prolong
if length <= 33:
line.append(seq.pop())
else:
break # leaves the inner loop
#end else
#end inner loop

for each in line:
# print each,
print "\b" # after the line is printed, it removes the last space from
the previous line

#Main
#@@ add a check to detect stand alone operation
if (__name__ == "__main__"):
seq = [1, 2, 3, 4, 56, 76, 100, 99, 56, 29, 82,93, 74, 48, 95, 43, 25, 36,
71, 100, 100, 100, 100, 13, 100,37, 86, 100, 100]
print "start function"
presentNums(seq)
#end main

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