analyze_mp3_in_place gives error when one chunk covers entire file

[LukeHearon]

Traceback:

Traceback (most recent call last):
  File "/home/luke/r projects/BuzzDetect/environment/lib/python3.9/site-packages/IPython/core/interactiveshell.py", line 3526, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-3-712912f8d1e8>", line 1, in <module>
    analyze_mp3_batch(modelname = "fullwav", directory_in = "./audio_in", directory_out = "./output", frameLength = 1500, frameHop = 750, chunklength_hr = 0.25)
  File "<ipython-input-2-ad1f2c0febdd>", line 103, in analyze_mp3_batch
    analysis_df = analyze_mp3_in_place(model = model, classes=classes, mp3_in = file, frameLength = frameLength, frameHop = frameHop, chunklength_hr = chunklength_hr)
  File "<ipython-input-2-ad1f2c0febdd>", line 63, in analyze_mp3_in_place
    full_analysis = pd.concat(analysis_list)
  File "/home/luke/r projects/BuzzDetect/environment/lib/python3.9/site-packages/pandas/core/reshape/concat.py", line 380, in concat
    op = _Concatenator(
  File "/home/luke/r projects/BuzzDetect/environment/lib/python3.9/site-packages/pandas/core/reshape/concat.py", line 443, in __init__
    objs, keys = self._clean_keys_and_objs(objs, keys)
  File "/home/luke/r projects/BuzzDetect/environment/lib/python3.9/site-packages/pandas/core/reshape/concat.py", line 505, in _clean_keys_and_objs
    raise ValueError("No objects to concatenate")
ValueError: No objects to concatenate

My guess as to why this happens (untested atm): When chunk size > file duration, analyze_mp3_in_place makes an analysis_list of length 1 with a single pd.DataFrame. This makes concat angry. I would rather it just returns the single DataFrame, but I'm having trouble implementing that at the moment (what's the equivalent of unlist()?

[LukeHearon]

Resolved by writing results per-chunk (a change I made for other reasons, but this is a nice side effect!)