GT.save() saves only to .png file

[SamuMazzi]

Prework

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• If there is already a relevant issue, whether open or closed, comment on the existing thread instead of posting a new issue.

Description

In the documentation is stated

file
The name of the file to save the image to. Accepts names ending with .png, .bmp, and other
image extensions. Also accepts the extension .pdf.

but actually right now any format that will be insterted when saving the table to file will be replaced by .png extension. This is probably related to #499 which edited these lines:

  -  if not Path(file).suffix:
  -     file += ".png"
  +  file = str(Path(file).with_suffix(".png"))

with the problem that .with_suffix always put the desired extension.

I can also create a PR. It seems a pretty straightforward fix, but I'd like to have a confirmation about this bug, thanks.

Reproducible example

from great_tables import GT
from great_tables.data import sp500

# Define the start and end dates for the data range
start_date = "2010-06-07"
end_date = "2010-06-14"

# Filter sp500 using Pandas to dates between `start_date` and `end_date`
sp500_mini = sp500[(sp500["date"] >= start_date) & (sp500["date"] <= end_date)]

# Create a gt table based on the `sp500_mini` table data
table = (
    GT(sp500_mini)
    .tab_header(title="S&P 500", subtitle=f"{start_date} to {end_date}")
    .fmt_currency(columns=["open", "high", "low", "close"])
    .fmt_date(columns="date", date_style="wd_m_day_year")
    .fmt_number(columns="volume", compact=True)
    .cols_hide(columns="adj_close")
)

table.save("sp500_mini.pdf")

You'll see a file sp500_mini.png

Expected result

It should have saved a file named sp500_mini.pdf

Development environment

• Operating System: Linux, Ubuntu 24.04
• great_tables Version: 0.16.1

[jrycw]

@SamuMazzi , thanks so much for reporting this.

For now, at least two bugs need to be fixed:

• The suffix bug mentioned in this issue.
• Reverting to saving the file using a temporary file to feed into the browser, as suggested in save: investigate use of base64 encoded urls in headless browser #518.

@machow and @rich-iannone, could you help address these issues? GT.save() is a crucial function in our library. (Apologies for the potential bugs—I'm currently on Chinese New Year holiday and may have limited access to a computer.)