TypeError: '>' not supported between instances of 'numpy.ndarray' and 'str'

Question

Basic rundown of what I want the program to do:

Aubio prints the frequency (pitch) and volume (volume) from what's being input from the microphone

I want to iterate over the dictionary, and based on which frequency is output, print the color matching which key in the dictionary the frequency from samples is being put out

I keep getting this error:

Traceback (most recent call last):
TypeError: '>' not supported between instances of 'numpy.ndarray' and 'str'

Would anyone be able to help me? The code in question is the for statement

import aubio
import numpy as num
import pyaudio
import sys

# Some constants for setting the PyAudio and the
# Aubio.
BUFFER_SIZE = 2048
CHANNELS = 1
FORMAT = pyaudio.paFloat32
METHOD = "default"
SAMPLE_RATE = 44100
HOP_SIZE = BUFFER_SIZE//2
PERIOD_SIZE_IN_FRAME = HOP_SIZE
index = 0

def main(args):

    # Initiating PyAudio object.
    pA = pyaudio.PyAudio()
    # Open the microphone stream.
    mic = pA.open(format=FORMAT, channels=CHANNELS,
                  rate=SAMPLE_RATE, input=True,
                  frames_per_buffer=PERIOD_SIZE_IN_FRAME)

    # Initiating Aubio's pitch detection object.
    pDetection = aubio.pitch(METHOD, BUFFER_SIZE,
                             HOP_SIZE, SAMPLE_RATE)
    # Set unit.
    pDetection.set_unit("Hz")
    # Frequency under -40 dB will considered
    # as a silence.
    pDetection.set_silence(-40)

    # Infinite loop!
    while True:

        # Always listening to the microphone.
        data = mic.read(PERIOD_SIZE_IN_FRAME)
        # Convert into number that Aubio understand.
        samples = num.fromstring(data,
                                 dtype=aubio.float_type)
        # Finally get the pitch.
        pitch = pDetection(samples)[0]
        # Compute the energy (volume)
        # of the current frame.
        volume = num.sum(samples**2)/len(samples)
        # Format the volume output so it only
        # displays at most six numbers behind 0.
        volume = "{:6f}".format(volume)

        answer = pitch_detection(samples)

        # Finally print the pitch and the volume.
        print(str(pitch) + " " + str(volume) + (str(answer)))


def pitch_detection(samples):
    colordict = {
        (0.0, 13.99): "Red",
        (14.00, 250.00): "Blue",
    }

    for index, key in enumerate(colordict, start=0):
        if samples > colordict[key][0] and samples < colordict[key][1]:
            return key
        return "Not Found"


if __name__ == "__main__":
    main(sys.argv)

Answer 1

samples is a numpy array. colordict[key][0] is a char (since colordict[key] is a text like "Red", the [0] will get first char from that string "R")

Your comparision if samples > colordict[key][0] and samples < colordict[key][1]: is comparing numpy array with a char and that fails.

Now, I'm not sure what you really want. if you mean key[0] and key[1] (to get each value from the key separately) then you would need to compare to a single float, not samples (which contain multiple values - it is an array) or maybe iterate over samples to compare?

Answer 2

for index, key in enumerate(colordict):
    if pitch > key[0] and pitch < key[1]:
        return colordict[key]

Ended up fixing it. Thank you all <3