Add auto index column

[erictzimas]

Fixes #90.

[codecov]

Codecov Report

Merging #106 (b2ca525) into master (1ab53a5) will increase coverage by 0.27%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #106      +/-   ##
==========================================
+ Coverage   87.68%   87.96%   +0.27%     
==========================================
  Files           3        3              
  Lines        1535     1562      +27     
==========================================
+ Hits         1346     1374      +28     
+ Misses        189      188       -1     

Flag	Coverage Δ
GHA_Ubuntu	87.96% <100.00%> (+0.27%)	⬆️
GHA_Windows	87.96% <100.00%> (+0.27%)	⬆️
GHA_macOS	87.96% <100.00%> (+0.27%)	⬆️

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Impacted Files	Coverage Δ
src/prettytable/prettytable.py	82.76% <100.00%> (+0.18%)	⬆️
tests/test_prettytable.py	100.00% <100.00%> (ø)

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[erictzimas]

Should i add a test for this function? how should i handle those 5 failing checks?

[hugovk]

Thanks for the PR!

Please could you add tests to tests/test_prettytable.py? Just let me know if you're not sure how to do that, and I can help out.

We can ignore the 3.10-dev failures for now, it's unrelated and caused by pytest not yet supporting 3.10 beta.

[erictzimas]

I will work on it, thank you!

[hugovk]

So this takes a table like this:

+-----------+------+------------+-----------------+
| City name | Area | Population | Annual Rainfall |
+-----------+------+------------+-----------------+
|  Adelaide | 1295 |  1158259   |      600.5      |
|  Brisbane | 5905 |  1857594   |      1146.4     |
|   Darwin  | 112  |   120900   |      1714.7     |
|   Hobart  | 1357 |   205556   |      619.5      |
|   Sydney  | 2058 |  4336374   |      1214.8     |
| Melbourne | 1566 |  3806092   |      646.9      |
|   Perth   | 5386 |  1554769   |      869.4      |
+-----------+------+------------+-----------------+

And adds an index to the right column:

+-----------+------+------------+-----------------+-------+
| City name | Area | Population | Annual Rainfall | Index |
+-----------+------+------------+-----------------+-------+
|  Adelaide | 1295 |  1158259   |      600.5      |   1   |
|  Brisbane | 5905 |  1857594   |      1146.4     |   2   |
|   Darwin  | 112  |   120900   |      1714.7     |   3   |
|   Hobart  | 1357 |   205556   |      619.5      |   4   |
|   Sydney  | 2058 |  4336374   |      1214.8     |   5   |
| Melbourne | 1566 |  3806092   |      646.9      |   6   |
|   Perth   | 5386 |  1554769   |      869.4      |   7   |
+-----------+------+------------+-----------------+-------+

However, @yanhuihang's example in #90 showed the index on the left column:

+-------+----------------------+----------------------+
| Index |          a           |          b           |
+-------+----------------------+----------------------+
|   1   |  0.8373683108488006  | -1.9662674211289342  |
|   2   |  0.8166690183400099  | -0.6827019085998253  |
|   3   | -0.34864565952912674 | -0.3828836864526866  |
|   4   |  -0.786195405989435  | -0.28278650269529015 |
|   5   | -0.7737543534146584  | 0.39198996847252016  |
|   6   |  1.2756295710689314  | 0.24976436160178775  |
|   7   |  -2.24766869070198   | -1.0958173510686795  |
|   8   | -0.2123610818363809  | -0.17583602522710734 |
|   9   | -0.9998924564529872  |  -0.78502826234026   |
|   10  |  -0.850991227375058  |  0.3267603399304381  |
+-------+----------------------+----------------------+

Would it be better on the left?

And should it be possible to set the column's field name to something else via a parameter? It can default to "Index".

[erictzimas]

Taking everything you said into consideration, I think i will remove valign and align as it is not necessary to have a separate formatting in the index column, i will add a parameter that represents the name of the index column and i will try to add the column on the left as I agree, this how it is normally done. Thank you very much for the guidance.

[erictzimas]

I modified the function to add the column on the left, and added the fieldname parameter, i did not remove valign and align since it does not seem to work if i do not specify this attributes when adding a new column as in add_column()

def add_column(self, fieldname, column, align="c", valign="t"):

        """Add a column to the table.

        Arguments:

        fieldname - name of the field to contain the new column of data
        column - column of data, should be a list with as many elements as the
        table has rows
        align - desired alignment for this column - "l" for left, "c" for centre and
            "r" for right
        valign - desired vertical alignment for new columns - "t" for top,
            "m" for middle and "b" for bottom"""

        if len(self._rows) in (0, len(column)):
            self._validate_align(align)
            self._validate_valign(valign)
            self._field_names.append(fieldname)
            self._align[fieldname] = align
            self._valign[fieldname] = valign
            for i in range(0, len(column)):
                if len(self._rows) < i + 1:
                    self._rows.append([])
                self._rows[i].append(column[i])
        else:
            raise Exception(
                f"Column length {len(column)} does not match number of rows "
                f"{len(self._rows)}"
            )

If that is ok please inform me so i can create a PR that also covers the _valign parameter, thank you.

[hugovk]

Thank you very much!

[mailsanchu]

Is this index broken if you apply sort?

[hugovk]

It adds a column to the data, so if you sort after adding, yes. So it's best sort first and add the index last.

[mailsanchu]

Cool Is it possible to formatted index like 001, 002 etc ?

[hugovk]

No.

[mailsanchu]

No worries

[hugovk]

You can always manually add a column with whatever data you want, including numbers formatted however you like.

[mailsanchu]

Yes I have done exactly that. Thanks

my_list.sort(key=lambda a: a[1])
for idx, val in enumerate(my_list):
    val.insert(0, f"{(idx + 1):0>3}")