Jupyter crashes when running imported function from another .py file

Question

I'm working on a research project that involves detecting hand gestures with WiFi CSI data. I basically have to record samples and then select the 20-packet-long interval during which the gesture occurs. I'm writing a script using ipywidgets to display the original spectrogram, ask for the first index of the sequence, show cropped spectrogram, and ask for confirmation before writing the clean data to a file. The script is imported from a .py file to an ipynb notebook where the prompts will show.

The problem is that every time I run the imported cleaner function, the kernel crashes. This happens both on a local machine and Google Colab.

Here's all the relevant code:

# data_cleaner.py

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import csiread # exports csv directly from pcap file!!
import ipywidgets as widgets # --> user interaction in Jupyter
from IPython.display import clear_output, display

def cleaner(csifile, gesture_length):
    # Extract csi directly from pcap file
    print('testing...') # not even this runs...
    csifile = '/content/REU/csi samples/csi_palmfist_1.pcap'
    csidata = csiread.Nexmon(csifile, chip='4339', bw=20)
    csidata.read()
    df1 = pd.DataFrame(csidata.csi)
    
    magMatrix = df1.applymap(abs) # magnitude matrix
    
    # define the useless subcarriers
    garbage = [1, 0, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38] # 14 removed
    
    cleaned = df1.drop(garbage, axis = 1)
    # display(cleaned)
    
    # amplitude visualization
    magMatrix = cleaned.applymap(np.abs)
    subcarLineChart(magMatrix)
    subcarSpectrogram(magMatrix)
    
    # smoothen the magnitude chart
    # apply is essentially map but passes each row instead of each element
    magSmoothened = magMatrix.apply(lambda x: mov_avg(x, 3))
    subcarLineChart(magSmoothened)
    subcarSpectrogram(magSmoothened)
    
    
    # UI STARTS HERE
    # limit useful gesture length to predefined value
    
    start_index = widgets.Text(
        value = '',
        description = 'Index for first packet in {}-packet sequence containing gesture:'.format(length)
        )
    extract_btn = widgets.Button(
        desciption = 'Extract'
        )
    
    extract_btn.on_click(handle_extract)
    
    # START = 
    
    # crop selected interval
    # btw: mag means magnitude
    # magSelected = magSmoothened[START:(START+LENGTH)]
    
    # show selected interval
    # subcarLineChart(magSelected)
    # subcarSpectrogram(magSelected)
    

## UI LOGIC
def handle_extract():
    magSelected = magSmoothened[START:(START+LENGTH)]
    subcarLineChart(magSelected)
    subcarSpectrogram(magSelected)
    
    display("Does this match what you were trying to extract? \n    If not, re-run the program. (ctrl-f9 on windows)\n")
    confirm_btn = widgets.Button(
        description = 'Yes, looks good'
        )
    confirm_btn.on_click(handle_confirm)
    
def handle_confirm():
    print('writes to file...')

## VISUALIZATION FUNCTIONS
from matplotlib import colors

def subcarLineChart(gph, log = False): # log: use log scale or not
    packet_index = len(gph.index)
    
    fig = plt.figure()
    ax1 = fig.add_subplot(111)
    plt.title("Magnitude of Signal by Channel and Packet Number")
    plt.xlabel("Packet #")
    plt.ylabel("Magnitude")
    ax1.set_yscale("log") if log else None
    
    num_subcarriers = len(gph.columns)
    num_samples = len(gph)
    for subcar_index in range(num_subcarriers):
        ax1.plot(
            range(num_samples),
            gph.iloc[:,subcar_index],
            lw = .25,
            label = subcar_index
        )
    
    plt.show()

def subcarSpectrogram(gph, log = False, subcar_start = 0, subcar_end = -1): # log: use log scale or not
    subcar_end = len(gph.iloc[0]) if subcar_end == -1 else subcar_end # replace -1 with valid final index
    plt.imshow(
    gph,
    # extent --> left, rigth, bottom, top
    extent = (subcar_start, subcar_end, len(gph), 0),
    norm = colors.LogNorm() if log else None)
    plt.xlabel('Subcarriers')
    plt.ylabel('Packet #')
    plt.colorbar(
      label = 'intensity')
    
    plt.show()
    
def mov_avg(arr, width):
    return np.convolve(arr, np.ones(width), 'valid') / width

# interactive data cleaning.ipynb
!pip install csiread

from google.colab import drive
import sys
drive.mount('/AshkanDrive')
!ln -s '/AshkanDrive/MyDrive/google_colab_files_for_CSI' '/content/REU'
filepath = '/content/REU/csi samples/old_testing_data/csi_palmfist_1.pcap'

sys.path.insert(0, '/content/REU/utils/')
from data_cleaner import cleaner

cleaner(filepath, 20) # 20 packets should be fine to fit all gestures

Answer 1

The code you provided seems to be missing a few necessary components and has some errors that could potentially lead to crashes. Here are some observations and suggestions to address these issues:

1. Missing code: The code snippet you shared does not include the imports for csiread and its usage to read CSI data from a pcap file. Please ensure that you have imported the necessary libraries and included the appropriate code to read CSI data from the file successfully.

2. Function parameters: The cleaner function accepts csifile and gesture_length as parameters, but you are hardcoding the csifile value inside the function. You should remove the line csifile = '/content/REU/csi samples/csi_palmfist_1.pcap' to use the parameter value instead.

3. Widget description error: In the handle_extract function, there is a typo in the description attribute of the extract_btn widget. Change desciption to description to fix the error.

4. Undefined variables: The variables START, LENGTH, magSmoothened, and subcarLineChart are referenced in the code but not defined within the cleaner function. Make sure these variables and the subcarLineChart function are defined and accessible within the cleaner function's scope.

5. Displaying non-string values: In the handle_extract function, you are using the display() function to show the confirmation message, which includes non-string values. To display the message correctly, you should convert the message to a string before passing it to display(). For example: display(str("Does this match what you were trying to extract? \n If not, re-run the program. (ctrl-f9 on windows)\n")).

6. Callback functions: It seems that the callback functions handle_extract() and handle_confirm() are defined inside the cleaner function. This might cause issues with the callbacks not being recognized. It's recommended to define these callback functions outside the cleaner function to ensure proper execution.

By addressing these issues and ensuring that the missing parts of the code are properly implemented, you should be able to run the cleaner function without crashing the kernel.