[Bug]: `fontsize` in tables not working

[acgc99]

Bug summary

Specifying fontsize kwarg in matplotlib.pyplot.table doesn't have any effect.

Code for reproduction

import matplotlib.pyplot as plt
import numpy as np

x = np.linspace(0, 10, 100)
y = x + 1
tableData = [['a', 1], ['b', 1]]

fig, ax = plt.subplots()
ax.plot(x, y)
t = ax.table(
    cellText=tableData,
    loc='top',
    cellLoc='center',
    fontsize=30
)
plt.show()

Actual outcome

Expected outcome

A table with bigger font size.

Additional information

This works:

import matplotlib.pyplot as plt
import numpy as np

x = np.linspace(0, 10, 100)
y = x + 1
tableData = [['a', 1], ['b', 1]]

fig, ax = plt.subplots()
ax.plot(x, y)
t = ax.table(
    cellText=tableData,
    loc='top',
    cellLoc='center'
)
t.set_fontsize(30)  # <----------------
plt.show()

Operating system

Windows 11

Matplotlib Version

3.8.2

Matplotlib Backend

QtAgg

Python version

3.12.0

Jupyter version

No response

Installation

pip

[github-actions]

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[QuLogic]

It appears that fontsize is documented as a property because Table.set_fontsize exists. However, Table.set_fontsize does not set some direct attribute, but sets the font size on all Cells of the table, so this value would never be known later. From matplotlib.table.table, the Table is created first (passing through the fontsize keyword argument), and the Cells are added afterwards, meaning the fontsize is never given to the Cells.

To get this working, the fontsize argument will need to be passed through the add_cell calls somewhere here. This seems like a fairly straightforward Good First Issue.

[Kaustbh]

Hi @QuLogic can I make a PR?

[saikarna913]

@Kaustbh, can I create the pull request? Since I am a beginner, this can motivate me to Contribute.

[Kaustbh]

No problem you can work on it 👍, let me know if you need any help.

[saikarna913]

@Kaustbh, I’m facing issues installing Matplotlib in the development environment, both on my local desktop and in GitHub Codespaces. It’s throwing an import error, so I’m unable to test the code changes I’ve made.

Here’s what I’ve done so far:

1. Forked the Matplotlib repository.
2. Created a new environment and installed dependencies using:

   pip install -r requirements/dev/dev-requirements.txt

also tried in GitHub Codespaces by activating the environment with:

conda activate mpl-dev

4. Installed Matplotlib in editable mode with:

   python -m pip install --verbose --no-build-isolation --editable ".[dev]"

5. Also tried:

   python -m pip install --no-build-isolation --config-settings=editable-verbose=true --editable .

Despite these steps, I’m still encountering the import error. Could you help me figure out why this might be happening?

[NGWi]

also tried in GitHub Codespaces by activating the environment

@saikarna913 Just to confirm, you activated your virtual environment when you were trying locally?

Also, please provide the error messages you're getting.

[saikarna913]

@NGWi, it is working after clearing my old versions and the above code runs, so please review my pull request and suggest the changes