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pythonmatrix

Pretty print 2D list?


Is there a simple, built-in way to print a 2D Python list as a 2D matrix?

So this:

[["A", "B"], ["C", "D"]]

would become something like

A    B
C    D

I found the pprint module, but it doesn't seem to do what I want.


Solution

  • To make things interesting, let's try with a bigger matrix:

    matrix = [
       ["Ah!",  "We do have some Camembert", "sir"],
       ["It's a bit", "runny", "sir"],
       ["Well,",  "as a matter of fact it's", "very runny, sir"],
       ["I think it's runnier",  "than you",  "like it, sir"]
    ]
    
    s = [[str(e) for e in row] for row in matrix]
    lens = [max(map(len, col)) for col in zip(*s)]
    fmt = '\t'.join('{{:{}}}'.format(x) for x in lens)
    table = [fmt.format(*row) for row in s]
    print '\n'.join(table)
    

    Output:

    Ah!                     We do have some Camembert   sir            
    It's a bit              runny                       sir            
    Well,                   as a matter of fact it's    very runny, sir
    I think it's runnier    than you                    like it, sir  
    

    UPD: for multiline cells, something like this should work:

    text = [
        ["Ah!",  "We do have\nsome Camembert", "sir"],
        ["It's a bit", "runny", "sir"],
        ["Well,",  "as a matter\nof fact it's", "very runny,\nsir"],
        ["I think it's\nrunnier",  "than you",  "like it,\nsir"]
    ]
    
    from itertools import chain, izip_longest
    
    matrix = chain.from_iterable(
        izip_longest(
            *(x.splitlines() for x in y), 
            fillvalue='') 
        for y in text)
    

    And then apply the above code.

    See also http://pypi.python.org/pypi/texttable