#! /usr/bin/env python def get_keyboard_edges(firstnote = 21, lastnote = 108):    octaves = 10     # build template of white notes    scalew  = 12/7.    xw_temp = [i*scalew for i in range(0,7)]    # build template of black notes    scaleb  = 6/7.    xb_temp = [i*scaleb for i in [1,3,7,9,11]]     xb,xw = [],[]    for octave in range(octaves-1):        for i in xb_temp:            curnote = i+12*octave            if  curnote > firstnote-1 and curnote < lastnote+1:                xb = xb + [curnote]    for octave in range(octaves-1):        for i in xw_temp:            curnote = i+12*octave            if  curnote > firstnote-1 and curnote < lastnote+1:                xw = xw + [curnote]     return xb, xw, 2/3. *scaleb, 1/2. * scalew def create_keyboard_patches(firstnote, lastnote, ax = None):    import matplotlib.pyplot as plt    from matplotlib.path import Path    import matplotlib.patches as mpatches     blacks, whites, b_width, w_width = get_keyboard_edges(firstnote, lastnote)     if not ax:        fig = plt.figure()        ax = fig.add_subplot(111)     verts, codes = [], []    for white in whites:        verts += [ (white - w_width, 0), (white - w_width, 1), (white + w_width, 1),  (white + w_width, 0) ]        verts += [ (white - w_width, 0) ]        codes  += [Path.MOVETO] + [Path.LINETO] * 4    path = Path(verts, codes)    patch = mpatches.PathPatch(path, facecolor= 'white', edgecolor='black', lw=1)    ax.add_patch(patch)     verts, codes = [], []    for black in blacks:        verts +=  [ (black - b_width, 0.33), (black - b_width, 1), (black + b_width, 1),  (black + b_width, 0.33) ]        verts += [ (black - b_width, 0.33) ]        codes += [Path.MOVETO] + [Path.LINETO] * 4    path = Path(verts, codes)    patch = mpatches.PathPatch(path, facecolor= 'black', edgecolor='black', lw=1)    ax.add_patch(patch)     ax.axis(xmin = firstnote, xmax = lastnote) if __name__ == '__main__':     import matplotlib.pyplot as plt    create_keyboard_patches(firstnote = 58, lastnote = 84)    plt.show()