in the web app, processing of input table can cause a crash

[mtiberti]

Traceback is

  File "/Users/tiberti/devel/MAVISp/env/lib/python3.9/site-packages/streamlit/runtime/scriptrunner/script_runner.py", line 534, in _run_script
    exec(code, module.__dict__)
  File "/Users/tiberti/devel/MAVISp/pages/1_MAVISp_simple_mode.py", line 189, in <module>
    plots = plot_lolliplots(this_dataset_table)
  File "/Users/tiberti/devel/MAVISp/env/lib/python3.9/site-packages/streamlit/runtime/caching/cache_utils.py", line 212, in wrapper
    return cached_func(*args, **kwargs)
  File "/Users/tiberti/devel/MAVISp/env/lib/python3.9/site-packages/streamlit/runtime/caching/cache_utils.py", line 241, in __call__
    return self._get_or_create_cached_value(args, kwargs)
  File "/Users/tiberti/devel/MAVISp/env/lib/python3.9/site-packages/streamlit/runtime/caching/cache_utils.py", line 267, in _get_or_create_cached_value
    return self._handle_cache_miss(cache, value_key, func_args, func_kwargs)
  File "/Users/tiberti/devel/MAVISp/env/lib/python3.9/site-packages/streamlit/runtime/caching/cache_utils.py", line 321, in _handle_cache_miss
    computed_value = self._info.func(*func_args, **func_kwargs)
  File "/Users/tiberti/devel/MAVISp/streamlit_utils.py", line 120, in plot_lolliplots
    _, processed_df = process_input_for_dotplot(df, d_cutoff=0.3, r_cutoff=0.5, g_cutoff=0.3)
  File "/Users/tiberti/devel/MAVISp/dot_plot.py", line 313, in process_input
    df.replace(effect_code,
  File "/Users/tiberti/devel/MAVISp/env/lib/python3.9/site-packages/pandas/core/generic.py", line 7819, in replace
    return self.replace(
  File "/Users/tiberti/devel/MAVISp/env/lib/python3.9/site-packages/pandas/core/generic.py", line 7867, in replace
    new_data = self._mgr.replace_list(
  File "/Users/tiberti/devel/MAVISp/env/lib/python3.9/site-packages/pandas/core/internals/base.py", line 253, in replace_list
    bm = self.apply_with_block(
  File "/Users/tiberti/devel/MAVISp/env/lib/python3.9/site-packages/pandas/core/internals/managers.py", line 354, in apply
    applied = getattr(b, f)(**kwargs)
  File "/Users/tiberti/devel/MAVISp/env/lib/python3.9/site-packages/pandas/core/internals/blocks.py", line 865, in replace_list
    masks = list(masks)
  File "/Users/tiberti/devel/MAVISp/env/lib/python3.9/site-packages/pandas/core/internals/blocks.py", line 852, in <genexpr>
    compare_or_regex_search(
  File "/Users/tiberti/devel/MAVISp/env/lib/python3.9/site-packages/pandas/core/array_algos/replace.py", line 98, in compare_or_regex_search
    result = op(a)
  File "/Users/tiberti/devel/MAVISp/env/lib/python3.9/site-packages/numpy/lib/function_base.py", line 2372, in __call__
    return self._call_as_normal(*args, **kwargs)
  File "/Users/tiberti/devel/MAVISp/env/lib/python3.9/site-packages/numpy/lib/function_base.py", line 2365, in _call_as_normal
    return self._vectorize_call(func=func, args=vargs)
  File "/Users/tiberti/devel/MAVISp/env/lib/python3.9/site-packages/numpy/lib/function_base.py", line 2450, in _vectorize_call
    ufunc, otypes = self._get_ufunc_and_otypes(func=func, args=args)
  File "/Users/tiberti/devel/MAVISp/env/lib/python3.9/site-packages/numpy/lib/function_base.py", line 2406, in _get_ufunc_and_otypes
    raise ValueError('cannot call `vectorize` on size 0 inputs '
ValueError: cannot call `vectorize` on size 0 inputs unless `otypes` is set

this is most likely due to pandas-dev/pandas#54399