FutureWarning from pandas

[matt-barker94]

A future warning about pandas DataFrame.append method being deprecated in future pandas releases, and to replace with pandas.concat methods. I found this warning in plotly/plotly.py/packages/python/plotly/plotly/express/_core.py:271 but there may be other places in plotly when DataFrame.append method is used.

[BjoernLudwigPTB]

I just stumbled across those annoying warnings as well. Seems like a good first issue to me, so I will start to work on this now. Dev environment is already set up and right now I am identifying the spots where those changes need to be applied.

I will keep you updated as soon as there is a first commit.

[Bass2015]

Hi,
@BjoernLudwigPTB @nicolaskruchten
I saw you fixed this in a commit, but I'm still getting an error when I try to use plotly.express polar charts using streamlit.
And for some reason, it makes the app crash when it's deployed, but not when it runs on localhost.

python3.10/site-packages/plotly/express/_core.py:271: FutureWarning:

The frame.append method is deprecated and will be removed from pandas in a future version. Use pandas.concat instead

This is the piece of code where it happens:

def make_trace_kwargs(args, trace_spec, trace_data, mapping_labels, sizeref):
    """Populates a dict with arguments to update trace

    Parameters
    ----------
    args : dict
        args to be used for the trace
    trace_spec : NamedTuple
        which kind of trace to be used (has constructor, marginal etc.
        attributes)
    trace_data : pandas DataFrame
        data
    mapping_labels : dict
        to be used for hovertemplate
    sizeref : float
        marker sizeref

    Returns
    -------
    trace_patch : dict
        dict to be used to update trace
    fit_results : dict
        fit information to be used for trendlines
    """
    if "line_close" in args and args["line_close"]:
        trace_data = trace_data.append(trace_data.iloc[0])

I upgraded plotly to version 5.14.1, and still get this error

[BjoernLudwigPTB]

I saw you fixed this in a commit, but I'm still getting an error […]

Oh no, I must have missed that. 😞 But it seems to be already addressed by a8af752 two weeks ago.

[Bass2015]

Yeah, I just saw it's fixed, but still unreleased. Thanx for this tools, btw!

[JT-NHS-UHMBT]

Hi, when will the fix for this be released. I am still getting the warning when using plotly.express.line_polar:

Python311\Lib\site-packages\plotly\express\_core.py:271: FutureWarning:
The frame.append method is deprecated and will be removed from pandas in a future version. Use pandas.concat instead.

[alexcjohnson]

@JT-NHS-UHMBT - #4190 fixed this and was released in v5.15.0, what version do you have?

[JT-NHS-UHMBT]

@JT-NHS-UHMBT - #4190 fixed this and was released in v5.15.0, what version do you have?

Thanks @alexcjohnson all working now, I was using v5.11.0 - should have checked that first, silly mistake!

[MKimiSH]

Pandas gives another warning on groupby on categorical columns now, regarding the default values:

.../venv/lib/python3.10/site-packages/plotly/express/_core.py:2044: FutureWarning:

The default of observed=False is deprecated and will be changed to True in a future version of pandas. Pass observed=Fals
e to retain current behavior or observed=True to adopt the future default and silence this warning.

The easy solution would be to pass observed=False to that groupby call. Not sure if that is the desired behavior, though.

[alexcjohnson]

@MKimiSH this was fixed in #4437 (🙇 @arcanaxion) and will be included in the next release.