Python Sequences Chart

python_seq.html

<table border=1 cellpadding=5>
    <tr>
        <th>&nbsp;</th>
        <th>Lists</th>
        <th>Iterators</th>
    </tr>

    <tr>
        <th>Expressive</th>
        <td>
            <pre>
    result = [x*2 for x in lst]
            </pre>
        </td>
        <td>
            <pre>
    result = (x*2 for x in lst)
            </pre>
        </td>
    </tr>

    <tr>
        <th>Imperative</th>
        <td>
            <pre>
    result = []
    for x in lst:
        result.append(x*2)
            </pre>
        </td>
        <td>
            <pre>
    def result_iter():
        for x in lst:
            yield x * 2
    result = result_iter()
            </pre>
        </td>
    </tr>

    <tr>
        <th>Generalize</th>
        <td>
            <pre>
    def map(f, lst):
        result = []
        for item in lst:
            result.append(f(item))
        return result
            </pre>
        </td>
        <td>
            <pre>
    def imap(f, lst):
        for item in lst:
            yield f(item)
            </pre>
        </td>
    </tr>

    <tr>
        <th>Functional</th>
        <td>
            <pre>
    def double(x):
        return x * 2

    result = map(double, lst)
            </pre>
        </td>
        <td>
            <pre>
    def double(x):
        return x * 2

    result = itertools.imap(double, lst)
            </pre>
        </td>
    </tr>

    <tr valign="top">
        <th>Built ins</th>
        <td>
            <pre>
    lst[start:end]
    map(f, lst)
    filter(f, lst)

    any
    all
    sum

    len(lst)
            </pre>
        </td>
        <td>
            <pre>
    itertools.islice(seq, start, stop)
    itertools.imap(f, seq)
    itertools.ifilter(f, seq)

    any
    all
    sum

    itertools.ichain
    itertools.dropwhile
    itertools.groupby
    itertools.tee
    itertools.takewhile
            </pre>
        </td>
    </tr>

</table>