Question

I’ve been teaching myself Python at my new job, and really enjoying the language. I’ve written a short class to do some basic data manipulation, and I’m pretty confident about it.

But old habits from my structured/modular programming days are hard to break, and I know there must be a better way to write this. So, I was wondering if anyone would like to take a look at the following, and suggest some possible improvements, or put me on to a resource that could help me discover those for myself.

A quick note: The RandomItems root class was written by someone else, and I’m still wrapping my head around the itertools library. Also, this isn’t the entire module – just the class I’m working on, and it’s prerequisites.

What do you think?

import itertools
import urllib2
import random
import string

class RandomItems(object):
    """This is the root class for the randomizer subclasses. These
        are used to generate arbitrary content for each of the fields
        in a csv file data row. The purpose is to automatically generate
        content that can be used as functional testing fixture data.
    """
    def __iter__(self):
        while True:
            yield self.next()

    def slice(self, times):
        return itertools.islice(self, times)

class RandomWords(RandomItems):
    """Obtain a list of random real words from the internet, place them
        in an iterable list object, and provide a method for retrieving
        a subset of length 1-n, of random words from the root list.
    """
    def __init__(self):
        urls = [
            "http://dictionary-thesaurus.com/wordlists/Nouns%285,449%29.txt",
            "http://dictionary-thesaurus.com/wordlists/Verbs%284,874%29.txt",
            "http://dictionary-thesaurus.com/wordlists/Adjectives%2850%29.txt",
            "http://dictionary-thesaurus.com/wordlists/Adjectives%28929%29.txt",
            "http://dictionary-thesaurus.com/wordlists/DescriptiveActionWords%2835%29.txt",
            "http://dictionary-thesaurus.com/wordlists/WordsThatDescribe%2886%29.txt",
            "http://dictionary-thesaurus.com/wordlists/DescriptiveWords%2886%29.txt",
            "http://dictionary-thesaurus.com/wordlists/WordsFunToUse%28100%29.txt",
            "http://dictionary-thesaurus.com/wordlists/Materials%2847%29.txt",
            "http://dictionary-thesaurus.com/wordlists/NewsSubjects%28197%29.txt",
            "http://dictionary-thesaurus.com/wordlists/Skills%28341%29.txt",
            "http://dictionary-thesaurus.com/wordlists/TechnicalManualWords%281495%29.txt",
            "http://dictionary-thesaurus.com/wordlists/GRE_WordList%281264%29.txt"
        ]
        self._words = []
        for url in urls:
            urlresp = urllib2.urlopen(urllib2.Request(url))
            self._words.extend([word for word in urlresp.read().split("\r\n")])
        self._words = list(set(self._words)) # Removes duplicates
        self._words.sort() # sorts the list

    def next(self):
        """Return a single random word from the list
        """
        return random.choice(self._words)

    def get(self):
        """Return the entire list, if needed.
        """
        return self._words

    def wordcount(self):
        """Return the total number of words in the list
        """
        return len(self._words)

    def sublist(self,size=3):
        """Return a random segment of _size_ length. The default is 3 words.
        """
        segment = []
        for i in range(size):
            segment.append(self.next())
        #printable = " ".join(segment)        
        return segment

    def random_name(self):
        """Return a string-formatted list of 3 random words.
        """
        words = self.sublist()
        return "%s %s %s" % (words[0], words[1], words[2])

def main():
    """Just to see it work...
    """
    wl = RandomWords()
    print wl.wordcount()
    print wl.next()
    print wl.sublist()
    print 'Three Word Name = %s' % wl.random_name()
    #print wl.get()

if __name__ == "__main__":
    main()

Answer 1

Here are my five cents:

• Constructor should be called __init__.
• You could abolish some code by using random.sample, it does what your next() and sublist() does but it’s prepackaged.
• Override __iter__ (define the method in your class) and you can get rid of RandomIter. You can read more about at it in the docs (note Py3K, some stuff may not be relevant for lower version). You could use yield for this which as you may or may not know creates a generator, thus wasting little to no memory.
• random_name could use str.join instead. Note that you may need to convert the values if they are not guaranteed to be strings. This can be done through [str(x) for x in iterable] or in-built map.