Category: Python

Here: have a script to generate plaintext hexagonal lattices for you when you’re feeling blue.

import itertools
pattern1 = ". ."
pattern0 = "   "
def main(repeat,length):
  for _ in itertools.repeat(None, length):
  print (pattern1+pattern0)*repeat
  print (pattern0+pattern1)*repeat
if __name__ == "__main__":
    main(10,10)

. .   . .   . .   . .   . .   . .   . .   . .   . .   . .   
   . .   . .   . .   . .   . .   . .   . .   . .   . .   . .
. .   . .   . .   . .   . .   . .   . .   . .   . .   . .   
   . .   . .   . .   . .   . .   . .   . .   . .   . .   . .
. .   . .   . .   . .   . .   . .   . .   . .   . .   . .   
   . .   . .   . .   . .   . .   . .   . .   . .   . .   . .
. .   . .   . .   . .   . .   . .   . .   . .   . .   . .   
   . .   . .   . .   . .   . .   . .   . .   . .   . .   . .
. .   . .   . .   . .   . .   . .   . .   . .   . .   . .   
   . .   . .   . .   . .   . .   . .   . .   . .   . .   . .
. .   . .   . .   . .   . .   . .   . .   . .   . .   . .   
   . .   . .   . .   . .   . .   . .   . .   . .   . .   . .
. .   . .   . .   . .   . .   . .   . .   . .   . .   . .   
   . .   . .   . .   . .   . .   . .   . .   . .   . .   . .
. .   . .   . .   . .   . .   . .   . .   . .   . .   . .   
   . .   . .   . .   . .   . .   . .   . .   . .   . .   . .
. .   . .   . .   . .   . .   . .   . .   . .   . .   . .   
   . .   . .   . .   . .   . .   . .   . .   . .   . .   . .
. .   . .   . .   . .   . .   . .   . .   . .   . .   . .   
   . .   . .   . .   . .   . .   . .   . .   . .   . .   . .

Today, I wanted to code an efficient letter to Morse code translator in Python and whipped this up. I’ve found that a familiarity with many of Python’s lesser-known built-in functions is quite useful in situations such as this!

Just for fun, I encourage the reader to use this script to leave their comments in Morse.

#!usr/bin/python
#Catherine Ray
"""
morse.py {string} [{string} ... ]:
 Translates string of english letters and spaces to morse code.
"""
import string
import sys
if len(sys.argv)>=2:
 if sys.argv[1].isalpha():
  text = ''.join(sys.argv[1:]).lower()
  morse = ["01","1000","1010","100","0", "0010", "110", "0000", "00", "0111", "101", "0100", "11", "10", "111", "0110", "1101", "010", "000", "1", "001", "0001", "011", "1001", "1011", "1100"]  letter = map(chr, range(97, 123))
  LETTER_TO_MORSE = dict(zip(letter, morse))
  morse_out = [LETTER_TO_MORSE[x] for x in text]  print ' '.join(morse_out).replace("1","-").replace("0",".")
 else:
  "Restrict yourself to the english alphabet."
else: 
 print "Enter a string to translate, friend!"

Today, as I was writing a post on sorting in vim, I issued myself a challenge.

The challenge: without using a bash script, write a one liner that reads through all the lines in a file, sorts them and printed these sorted lines to stdout. Do so in under a minute without using the internet.

Before you continue, I encourage you to try it yourself. Get out a timer … Ready? Go!

In about 35 seconds, I had this:

print 'n'.join(sorted([line.strip() for line in open("file.txt")]))

Although this one-liner works, the filename is hardcorded. Quick fix (finished at 52 seconds):

import sys; print 'n'.join(sorted([line.strip() for line in open(sys.argv[1])]))

I find that self-issuing pseudorandom timed challenges is a fun way to train yourself to work under pressure. ‘Tis one of the many ways to gamify everyday life!

Sidenote: Do not fall into the trap of using one-liners in actual code. The Pythonic way to do this is:

import sys
try:
    with open(sys.argv[1]) as f:
        for line in f:
            print 'n'.join(sorted(line.strip())) 
except IOError:
    print "File does not exist."

The code on my blog will range in quality from “I’m waiting in line and have 10 minutes to code” to “I’ve been working on this all day.”

Let’s with begin some quick, semi-hardcoded scripts, shall we?

# dayofweek.py
import datetime
from sys import argv
from calendar import day_abbr #import day_name for full name
"""
Counts the amount of hits per weekday, given a file of data corresponding to "year month day amount-of hits"
"""
#starts with a zero counter array (each index corresponds to a weekday, 0:Sunday, 1:Monday, ...)
weekcount = [0]*7 #hits per day
argv = argv[1:] #get rid of script declaration in args
#make sure string has year, month, day, amount-of-hits-that-day
if len(argv) % 4 == 0:
  for c in range(0, len(argv),4):
    #increment slice so we are only looking at one set of (year, month, day, amount-of-hits-that-day) at one time
     if (a.isdigit() for a in argv[0+c:4+c]):
         year, month, day, count = int(argv[0+c]), int(argv[1+c]), int(argv[2+c]), int(argv[3+c]);
         #get index of day that the given date corresponds to
         daynum = int(datetime.date(year, month, day).strftime("%w"))
         #add the amount-of-hits-that-day to the counter
         weekcount[daynum] = weekcount[daynum] + count;
  #display days from most to least popular
  print 'n'.join([day_abbr[(sorted(range(7), key=lambda k: weekcount[k]))[d]] for d in range(7)])

Okay, we need some random data to test this bad boy on. Naively, we could create a random data set of valid days as follows:

# randomday.py
import random as r
f=[]for x in xrange(12):
 year = r.choice(range(1997, 2013))
 month = r.choice(range(1, 12))
 day = r.choice(range(1, 28))
 hits = r.choice(range(6666,9999))
 f.extend((year, month, day, hits))
print ' '.join(map(str,f))

An example of this output is:

2008 9 15 7311 2007 7 1 9812 2011 6 9 7721 2003 7 21 6736 2010 9 13 7776 1997 9 14 8776 1999 7 14 8617 2012 9 4 8208 2006 11 26 9689 2004 11 10 8952 1997 7 19 7799 2007 9 15 7858

We can feed these test values into our original script with a quick bash one-liner:

python dayofweek.py `python randomday.py`

We will receive the most and least popular weekdays in this random set of data:

Wed
Fri
Sat
Mon
Tue
Sun
Thu