Add header alignment attribute

[myheroyuki]

Fixes #102

[codecov]

Codecov Report

Merging #183 (1ab3eaa) into master (546a594) will increase coverage by 0.08%.
The diff coverage is 100.00%.

❗ Current head 1ab3eaa differs from pull request most recent head bb931ba. Consider uploading reports for the commit bb931ba to get more accurate results

@@            Coverage Diff             @@
##           master     #183      +/-   ##
==========================================
+ Coverage   94.03%   94.11%   +0.08%     
==========================================
  Files           5        5              
  Lines        2245     2295      +50     
==========================================
+ Hits         2111     2160      +49     
- Misses        134      135       +1     

Flag	Coverage Δ
macos-latest	94.11% <100.00%> (+0.08%)	⬆️
ubuntu-latest	94.11% <100.00%> (+0.08%)	⬆️
windows-latest	93.98% <100.00%> (+0.08%)	⬆️

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Impacted Files	Coverage Δ
src/prettytable/prettytable.py	90.39% <100.00%> (+0.20%)	⬆️
tests/test_prettytable.py	99.87% <100.00%> (-0.13%)	⬇️

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[hugovk]

Thank you!

[hugovk]

I only just released this in 3.4.0 and noticed a possible bug:

With this code:

from prettytable import PrettyTable

headers = [
    "cycle",
    "release",
    "latest",
    "latest release",
    "support",
    "eol",
    "codename",
    "link",
]
data = [
    {
        "cycle": "22.04 LTS",
        "codename": "Jammy Jellyfish",
        "support": "2027-04-02",
        "eol": "2032-04-01",
        "latest": "22.04.1",
        "link": "https://wiki.ubuntu.com/JammyJellyfish/ReleaseNotes/",
        "release": "2022-04-21",
        "latest release": "2022-08-11",
    },
    {
        "cycle": "21.10",
        "codename": "Impish Indri",
        "support": "2022-07-31",
        "eol": "2022-07-31",
        "latest": "21.10",
        "link": "https://wiki.ubuntu.com/ImpishIndri/ReleaseNotes/",
        "release": "2021-10-14",
        "latest release": "2021-10-14",
    },
    {
        "cycle": "21.04",
        "codename": "Hirsute Hippo",
        "support": "2022-01-20",
        "eol": "2022-01-20",
        "latest": "21.04",
        "link": "https://wiki.ubuntu.com/HirsuteHippo/ReleaseNotes/",
        "release": "2021-04-22",
        "latest release": "2021-04-22",
    },
    {
        "cycle": "20.10",
        "codename": "Groovy Gorilla",
        "support": "2021-07-22",
        "eol": "2021-07-22",
        "latest": "20.10",
        "release": "2020-10-22",
        "latest release": "2020-10-22",
    },
    {
        "cycle": "20.04 LTS",
        "codename": "Focal Fossa",
        "support": "2025-04-02",
        "eol": "2030-04-01",
        "latest": "20.04.4",
        "release": "2020-04-23",
        "latest release": "2022-02-25",
    },
    {
        "cycle": "19.10",
        "codename": "Karmic Koala",
        "support": "2020-07-06",
        "eol": "2020-07-06",
        "latest": "19.10",
        "release": "2019-10-17",
        "latest release": "2019-10-17",
    },
    {
        "cycle": "18.04 LTS",
        "codename": "Bionic Beaver",
        "support": "2023-04-02",
        "eol": "2028-04-01",
        "latest": "18.04.6",
        "link": "https://wiki.ubuntu.com/BionicBeaver/ReleaseNotes",
        "release": "2018-04-26",
        "latest release": "2021-09-17",
    },
    {
        "cycle": "16.04 LTS",
        "codename": "Xenial Xerus",
        "support": "2021-04-02",
        "eol": "2026-04-01",
        "latest": "16.04.7",
        "release": "2016-04-21",
        "latest release": "2020-08-13",
    },
    {
        "cycle": "14.04 LTS",
        "codename": "Trusty Tahr",
        "support": "2019-04-02",
        "eol": "2024-04-01",
        "latest": "14.04.6",
        "release": "2014-04-17",
        "latest release": "2019-03-07",
    },
]

x = PrettyTable()

for header in headers:
    col_data = [row[header] if header in row else "" for row in data]
    x.add_column(header, col_data)
    if header in ("cycle", "latest", "link"):
        x.align[header] = "l"

print(x)

Run with 3.3.0:

$ pip install --quiet prettytable==3.3.0 && python 1.py
+-----------+------------+---------+----------------+------------+------------+-----------------+------------------------------------------------------+
| cycle     |  release   | latest  | latest release |  support   |    eol     |     codename    | link                                                 |
+-----------+------------+---------+----------------+------------+------------+-----------------+------------------------------------------------------+
| 22.04 LTS | 2022-04-21 | 22.04.1 |   2022-08-11   | 2027-04-02 | 2032-04-01 | Jammy Jellyfish | https://wiki.ubuntu.com/JammyJellyfish/ReleaseNotes/ |
| 21.10     | 2021-10-14 | 21.10   |   2021-10-14   | 2022-07-31 | 2022-07-31 |   Impish Indri  | https://wiki.ubuntu.com/ImpishIndri/ReleaseNotes/    |
| 21.04     | 2021-04-22 | 21.04   |   2021-04-22   | 2022-01-20 | 2022-01-20 |  Hirsute Hippo  | https://wiki.ubuntu.com/HirsuteHippo/ReleaseNotes/   |
| 20.10     | 2020-10-22 | 20.10   |   2020-10-22   | 2021-07-22 | 2021-07-22 |  Groovy Gorilla |                                                      |
| 20.04 LTS | 2020-04-23 | 20.04.4 |   2022-02-25   | 2025-04-02 | 2030-04-01 |   Focal Fossa   |                                                      |
| 19.10     | 2019-10-17 | 19.10   |   2019-10-17   | 2020-07-06 | 2020-07-06 |   Karmic Koala  |                                                      |
| 18.04 LTS | 2018-04-26 | 18.04.6 |   2021-09-17   | 2023-04-02 | 2028-04-01 |  Bionic Beaver  | https://wiki.ubuntu.com/BionicBeaver/ReleaseNotes    |
| 16.04 LTS | 2016-04-21 | 16.04.7 |   2020-08-13   | 2021-04-02 | 2026-04-01 |   Xenial Xerus  |                                                      |
| 14.04 LTS | 2014-04-17 | 14.04.6 |   2019-03-07   | 2019-04-02 | 2024-04-01 |   Trusty Tahr   |                                                      |
+-----------+------------+---------+----------------+------------+------------+-----------------+------------------------------------------------------+

And with 3.4.0:

pip install --quiet prettytable==3.4.0 && python 1.py
+-----------+------------+---------+----------------+------------+------------+-----------------+------------------------------------------------------+
|   cycle   |  release   |  latest | latest release |  support   |    eol     |     codename    |                         link                         |
+-----------+------------+---------+----------------+------------+------------+-----------------+------------------------------------------------------+
| 22.04 LTS | 2022-04-21 | 22.04.1 |   2022-08-11   | 2027-04-02 | 2032-04-01 | Jammy Jellyfish | https://wiki.ubuntu.com/JammyJellyfish/ReleaseNotes/ |
| 21.10     | 2021-10-14 | 21.10   |   2021-10-14   | 2022-07-31 | 2022-07-31 |   Impish Indri  | https://wiki.ubuntu.com/ImpishIndri/ReleaseNotes/    |
| 21.04     | 2021-04-22 | 21.04   |   2021-04-22   | 2022-01-20 | 2022-01-20 |  Hirsute Hippo  | https://wiki.ubuntu.com/HirsuteHippo/ReleaseNotes/   |
| 20.10     | 2020-10-22 | 20.10   |   2020-10-22   | 2021-07-22 | 2021-07-22 |  Groovy Gorilla |                                                      |
| 20.04 LTS | 2020-04-23 | 20.04.4 |   2022-02-25   | 2025-04-02 | 2030-04-01 |   Focal Fossa   |                                                      |
| 19.10     | 2019-10-17 | 19.10   |   2019-10-17   | 2020-07-06 | 2020-07-06 |   Karmic Koala  |                                                      |
| 18.04 LTS | 2018-04-26 | 18.04.6 |   2021-09-17   | 2023-04-02 | 2028-04-01 |  Bionic Beaver  | https://wiki.ubuntu.com/BionicBeaver/ReleaseNotes    |
| 16.04 LTS | 2016-04-21 | 16.04.7 |   2020-08-13   | 2021-04-02 | 2026-04-01 |   Xenial Xerus  |                                                      |
| 14.04 LTS | 2014-04-17 | 14.04.6 |   2019-03-07   | 2019-04-02 | 2024-04-01 |   Trusty Tahr   |                                                      |
+-----------+------------+---------+----------------+------------+------------+-----------------+------------------------------------------------------+

Notice the different header alignment:

< | cycle     |  release   | latest  | latest release |  support   |    eol     |     codename    | link                                                 |
---
> |   cycle   |  release   |  latest | latest release |  support   |    eol     |     codename    |                         link                         |

So the code had set:

    if header in ("cycle", "latest", "link"):
        x.align[header] = "l"

In 3.3.0, the data and header were left-aligned.

In 3.4.0, only the data was left-aligned, the header was centre-aligned.

Is this a bug?

Should x.header_align override x.align?

But if there's no x.header_align, should the x.align behaviour not change from 3.3.0?

[osfrickler]

We noticed this change in OpenStack testing, too, and I think that default behavior should not change in a minor release, so I'd prefer this to be treated as a bug and get fixed.

[SeanMooney]

this is the openstack nova bug https://bugs.launchpad.net/nova/+bug/1988482

currently, it's blocking our stable branch for the last release.
we are working around it by pinning for now but ideally, this would be addressed
so that the default behaviour did not change outside of a major release.

currently I'm not sure how else we could "fix" this in oepnstack as we cannot raise minium on already released branches and see cant simply update the test as that would then fail with the older release of prettytable.

[SeanMooney]

actully i think i understand how to work around this in OpenStack so i have proposed
https://review.opendev.org/c/openstack/nova/+/855658 to manuly hardcode left alignment for now.

we can backport that as a workaround.

this is still likely a bug but we can maintain the old behavior by just setting both align and header_align

[hugovk]

I'll revert this and make a bug fix release.

Then this PR can be re-submitted, and we'll need extra tests to make sure things work with both header_align and align, with just one, and with neither.

Also the default header_align="c" in add_column needs checking:

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

[hugovk]

3.4.1 released:

https://pypi.org/project/prettytable/3.4.1/

[osfrickler]

Thx for the fast update, 3.4.1 works without failure for us