Python in Education Advocacy Article

[Michael Tobis]

Dear Python-in-Education types

For Python to gain the ground it ought to in educational settings will not happen automatically.

To do my part, I have decided that my first article in the Python Papers should be about comparing Python to other common first languages for learning and teaching. I'd appreciate your help.

Does language even matter pedagogically? If so what are Python's advantages and disadvantages? Should there be a universal first language of computing? Should it look more or less or exactly like Python?

To further discussion on this question I have set up a blog. (I hate that blogs are in reverse chronological order; I posted the articles in the opposite order than the reading order so you can read from top to bottom!)

In an effort to focus the conversation, I've asked a few language comparison questions that are relevant to Python's suitability as an educational language, each in its own blog entry. Please have a look, and make a stab at short answers to the questions. (If you have a long answer, please just link to it.) My idea is not to restrict people's ideas but to make an effort to provide some structure for the conversation.

It will be very interesting to see if this helps move the conversation forward. The best outcome would be if we discover "low-hanging fruit" to advance the cause. Please lend a hand.

see http://pencilscience.blogspot.com/

with pythonical regards,
Michael Tobis

[Toby Donaldson]

Michael,

On the sigcse list there was recently a coding challenge
(http://www.cs.duke.edu/csed/code) that asked for solutions to a word
frequency problem in various languages. I believe the author is
planning to eventually list all the solutions received (entries came
in many different languages); that could make for some interesting
comparisons.

I wrote one solution in Python, and one in Java, which I give below;
needless to say, I found the Python version far easier to write.

Toby

-------------------------------------------------------------------------------------------------------------------------------
import sys

if __name__ == '__main__':
# get the path from the command-line
fname = sys.argv[1]

# read in the file as a list of tokens
tokens = [tok.strip().lower() for tok in open(fname, 'r').read().split()]

# calculate the frequency of each token
freq = {}
for tok in tokens:
if tok in freq:
freq[tok] += 1
else:
freq[tok] = 1

# Sort the list in highest frequency to lowest frequency,
# with ties sorted by lexicographics order of the words.
# Uses the Python sort-decorate-unsort idiom. We sort by
# the negation of the frequency values to get the proper
# ordering.

lst = [(-freq[tok], tok) for tok in freq] # decorate
lst.sort() # sort
lst = [(-freq, tok) for freq, tok in lst] # undecorate

# print the results
for freq, tok in lst:
print '%s\t%s' % (freq, tok)

-------------------------------------------------------------------------------------------------------------------------------

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;
import java.util.TreeMap;
import java.util.TreeSet;

public class Puzzle {

public static void main(String[] args) throws IOException {
// get the file to process
String fname = args[0];

Scanner sc = new Scanner(new File(fname));

// initialize the map for the words and counts;
// a TreeMap is always ordered by keys
TreeMap<String, Integer> map = new TreeMap<String, Integer>();

// process the file a line at a time
while (sc.hasNextLine()) {
// chop each line into its constituent tokens
// "\\s+" is a regular expression that matches
one or more
// whitespace characters
String[] tokens = sc.nextLine().split("\\s+");

// make all the strings lower case, and remove
any excess whitespace
for (int i = 0; i < tokens.length; ++i) {
tokens[i] = tokens[i].toLowerCase().trim();
}

// add each token to the map
for (String tok : tokens) {
if (map.containsKey(tok)) {
map.put(tok, map.get(tok) + 1);
} else {
map.put(tok, 1);
}
}
}

// remove the empty string if it is present
map.remove("");

// sort the data by storing each word that occurs the
same number of
// times in a TreeMap of sets keyed by count; TreeSet stores its
// values in sorted order
TreeMap<Integer, TreeSet<String>> sortMap = new TreeMap<Integer,
TreeSet<String>>();
for (String tok : map.keySet()) {
int count = map.get(tok);
if (sortMap.containsKey(count)) {
TreeSet<String> arr = sortMap.get(count);
arr.add(tok);
sortMap.put(count, arr);
} else {
TreeSet<String> arr = new TreeSet<String>();
arr.add(tok);
sortMap.put(count, arr);
}
}

// print the data

// first reverse the keys to print data in the proper order
ArrayList<Integer> idx = new ArrayList<Integer>();
idx.addAll(sortMap.keySet());
Collections.reverse(idx);

// print it to stdout
for (Integer key : idx) {
TreeSet<String> toks = sortMap.get(key);
for (String t : toks) {
System.out.printf("%s\t%s\n", key, t);
}
}
}
}