Complex signal to square wave

Hello all!

I wrote a script in python that takes a binary file (output of the, convert it in a sequence of complex values and
applies a
variable threshold in order to convert that complex sequence in a square
The complex sequence already represent a square wave, but with a noise
distortions that I want to clean.
Now I would like to merge what I’ve done with the gnuradio language, and
this is
what I tried:

class my_top_block(gr.top_block):

def __init__(self):

    def block_cplx_to_sq (matrice):
        output1 = []
        d = ds = 0;
        de = len(matrice);
        while (d < de):

        [sequence of 'if..else' to find the correct value of 


            threshold = mean(matrice[min,max]);
            stad = std(matrice[min_std,max_std]);

            if stad <= 50:
                threshold = threshold - 100;

            if abs(matrice[d]) >= threshold:

            d = d + 1;
        return output1;

    src = gr.file_source(gr.complex, "Acq_petit", TRUE)
    BLCK = block_cplx_to_sq ();
    self.connect(src, BLCK)

The problem is that the program still requires something as input of
block_cplx_to_sq (and it should be the output of the file_source…).
Does anyone have any idea to help me? (maybe some gnuradio function that
I don’t
know that does something like this)

Thank you in advance,
Kind regards,