My first ever Python program, comments welcome
MRAB
python at mrabarnett.plus.com
Sat Jul 21 15:40:46 EDT 2012
On 21/07/2012 20:08, Lipska the Kat wrote:
> Greetings Pythoners
>
> A short while back I posted a message that described a task I had set
> myself. I wanted to implement the following bash shell script in Python
>
> Here's the script
>
> sort -nr $1 | head -${2:-10}
>
> this script takes a filename and an optional number of lines to display
> and sorts the lines in numerical order, printing them to standard out.
> if no optional number of lines are input the script prints 10 lines
>
> Here's the file.
>
> 50 Parrots
> 12 Storage Jars
> 6 Lemon Currys
> 2 Pythons
> 14 Spam Fritters
> 23 Flying Circuses
> 1 Meaning Of Life
> 123 Holy Grails
> 76 Secret Policemans Balls
> 8 Something Completely Differents
> 12 Lives of Brian
> 49 Spatulas
>
>
> ... and here's my very first attempt at a Python program
> I'd be interested to know what you think, you can't hurt my feelings
> just be brutal (but fair). There is very little error checking as you
> can see and I'm sure you can crash the program easily.
> 'Better' implementations most welcome
>
> #! /usr/bin/env python3.2
>
> import fileinput
> from sys import argv
> from operator import itemgetter
>
> l=[]
> t = tuple
What's the purpose of this line?
> filename=argv[1]
> lineCount=10
>
> with fileinput.input(files=(filename)) as f:
> for line in f:
> t=(line.split('\t'))
> t[0]=int(t[0])
> l.append(t)
> l=sorted(l, key=itemgetter(0))
Short is:
l.sort(key=itemgetter(0))
>
> try:
> inCount = int(argv[2])
> lineCount = inCount
You may as well say:
lineCount = int(argv[2])
> except IndexError:
> #just catch the error and continue
> None
The do-nothing statement is:
pass
>
> for c in range(lineCount):
> t=l[c]
If there are fewer than 'lineCount' lines, this will raise IndexError.
You could do this instead:
for t in l[ : lineCount]:
> print(t[0], t[1], sep='\t', end='')
>
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