title: How do I get numpy arrays (wav signals) out of a dataframe to process?
body: <p>I compiled a dataframe with over 300K wav signals in the form of a numpy array and then exported them to a .csv for later use. The dataframe looks like this:</p>
  <pre><code>        signal_wav                                          label
  323302  [-0.03637242, -0.04163716, -0.0382735, -0.0407...   tag1
  323303  [0.0052252985, 0.0074647125, 0.0071932683, 0.0...   tag2
  323304  [-0.05064101, -0.0662319, -0.109769195, -0.110...   tag3
  323305  [-0.0332708, -0.029734522, -0.025742473, -0.02...   tag4
  323306  [-0.0069274902, -0.008087158, -0.008178711, -0...   tag5
  </code></pre>
  <p>Then I created a function to extract features from each signal within the dataframe like this:</p>
  <pre><code>def get_mfcc(signals, sr):
      
      all_signal_mfccs = []
      for signal in signals:
          mfcc = librosa.feature.mfcc(y=signal, sr=sr)
          all_signal_mfccs.append(mfcc)
          
      feat_df = pd.DataFrame(all_signal_mfccs)
      
      return feat_df
  </code></pre>
  <p>However, when running the function I keep recieving the error &quot;ParameterError: Audio data must be of type numpy.ndarray&quot;. I tried adding a portion of code that converts the original signal within the row from the dataframe using &quot;np.asarry&quot; or &quot;np.array&quot; but then I get the error saying that the data is a not in float format.</p>
  <p>I understand it might have something to do with the dtypes, maybe? I also tried &quot;pd.to_numeric&quot; for the &quot;signal_wav&quot; column specifically but that didnt work either.</p>
  <p>All I am trying to do is, iterate through the &quot;signal_wav&quot; column and read each array to process them and extract its features.</p>