treetable

Helper to pretty print an ascii table with a tree-like structure.

Installation and requirements

treetable requires at least python3.6.

pip3 install treetable

Quick example

treetable allows to easily output complex ascii tables like

         ||                 ||              metrics
         ||       info      ||      train     |       test
name     ||  index  status  ||     Pr  recall |   auc  accuracy
RirpUoE  ||  21     L       ||  94.4%   56.4% | 46.3%     79.6%
wtAYHBf  ||                 ||
j        ||                 ||
rLsITTK  ||  47     q       ||  66.0%   84.8% | 46.5%     64.9%
S        ||                 ||
Uumlvod  ||  49     Z       ||  63.1%   99.8% | 94.6%     10.6%
SmIsO    ||                 ||
rzXlDqM  ||  32     J       ||  48.8%   33.5% | 30.8%     94.2%
PyCX     ||                 ||

Usage and examples

The main function is treetable.treetable. It takes a tree-like structure to represent the table. For instance, I could have a sub-table info and a sub-table metrics, each one being recursively composed of other sub-tables.

Each extra level of sub-tables use a different separator (by default up to 3 levels but you can provide extra separators with the separators arguments).

At the leaf level of the tree, a format string (that can be passed to the format builtin) can be specified. Let's take an example

from treetable import table, group, leaf

mytable = table([
    group('info', [
        leaf('name'),
        leaf('index')]),
    group('metrics', align='>', groups=[
        leaf('speed', '.0f'),
        leaf('accuracy', '.1%'),
        leaf('special', '.1%', align='=')]),
])

The lines of the table should be provided following a list of nested dictionaries with the same shape, for instance:

lines = [
    {'info': {'name': 'bob', 'index': 4}, 'metrics':{'speed': 200, 'accuracy': 0.21, 'special': 0.1}},
    {'info': {'name': 'alice', 'index': 2}, 'metrics':{'speed': 67, 'accuracy': 0.45, 'special': 4.56}},
]

Now running print(treetable(lines, groups)) will give you

    info     |         metrics
name   index | speed  accuracy  special
bob    4     |   200     21.0%   10.0%
alice  2     |    67     45.0%   456.0%

table, group and leaf are all node definition functions. They all accept the same arguments and differ only in the order of positional arguments. When defined in a leaf node, the arguments will directly influence how the data is rendered. In group nodes or the root (aka table) node, they will override the default behaviors in descendent leafs. The following arguments are defined:

key: access key in the lines data structure.
groups (only for group and table nodes): list of sub-tables.
display: display name used, when different to the name to access the value in the lines structure.
align: alignment of text, either '<' (left aligned), '=' (centered) or '>' (right aligned).
wrap: wrap text beyond a certain number of characters. No smart wrapping, this will wrap exactly at the limit characters by inserting a new line.
missing: value used when a specific key is not present. Default is ''.
shorten: automatically shorten columns names. They are not shorten any more than the width of the underlying column and a long enough prefix is kept to remove any possible ambiguity with other columns in the same sub-tab le.

For instance, when using shorten=True with the above table:

  info   |       metrics
name   i | spee  accur  specia
bob    4 |  200  21.0%  10.0%
alice  2 |   67  45.0%  456.0%

name wasn't shortened because alice is longer than name so there would be no point in shortening it. However speed is kept long enough to avoid ambiguity with special.

When setting wrap=3 for the name column we obtain the following:

 info  |       metrics
nam  i | spee  accur  specia
bob  4 |  200  21.0%  10.0%
ali  2 |   67  45.0%  456.0%
ce     |

It is possible to customize the column separators by passing separators to the treetable function. Its default value is [' ', ' | ', ' || '].

Colors

It is possible to use ANSI color codes by passing a list of color codes to treetable() with the colors argument. The i-th line (including headers) will have the color colors[i % len(colors]. For instance:

treetable(lines, mytable, colors=["30", "39"])

For a good reference on ANSI color codes, checkout this stackoverflow question.

License