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copied!<p>I'm unaware of a library doing what you ask (but I only glanced at the <code>sqldf</code> documentation), however nothing of what you asked really requires a library, they are one-liners in python (and you could of course abstract the functionality creating a function rather than a simple list comprehension...)</p> <blockquote> <p>Set A= {1,0}, a list B = [[1,1],[2,3]]. I would like to find all rows in B where the second column is one of the values in A.</p> </blockquote> <pre><code>>>> a = set([1, 0]) >>> b = [[1,1],[2,3]] >>> [l for l in b if l[1] in a] [[1, 1]] </code></pre> <blockquote> <p>I have 2 CSV files. I want to find out all the rows where the values of some column from the two files match.</p> </blockquote> <pre><code>>>> f1 = [[1, 2, 3], [4, 5, 6]] >>> f2 = [[0, 2, 8], [7, 7, 7]] >>> [tuple_ for tuple_ in zip(f1, f2) if tuple_[0][1] == tuple_[1][1]] [([1, 2, 3], [0, 2, 8])] </code></pre> <hr> <p><strong>EDIT:</strong> If memory usage is a problem you should use generators instead of lists. For example:</p> <pre><code>>>> zip(f1, f2) [([1, 2, 3], [0, 2, 8]), ([4, 5, 6], [7, 7, 7])] </code></pre> <p>but using generators:</p> <pre><code>>>> import itertools as it >>> gen = it.izip(f1, f2) >>> gen <itertools.izip object at 0x1f24ab8> >>> next(gen) ([1, 2, 3], [0, 2, 8]) >>> next(gen) ([4, 5, 6], [7, 7, 7]) </code></pre> <p>And for the data source:</p> <pre><code>>>> [line for line in f1] [[1, 2, 3], [4, 5, 6]] </code></pre> <p>translate as generator as:</p> <pre><code>>>> gen = (line for line in f1) >>> gen <generator object <genexpr> at 0x1f159b0> >>> next(gen) [1, 2, 3] >>> next(gen) [4, 5, 6] </code></pre>

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