csv_to_bvh.py

import csv
import os
import bpy

objects = bpy.context.scene.objects

empties = []

for object in objects:
    if object.type == 'EMPTY':
        empties.append(object)
        
print(empties)

filename = 'csv_joined.csv'
directory = r'hmr/output/csv_joined'  # <-- if you have linux or osx

fullpath = os.path.join(directory, filename)

with open(fullpath, 'r', newline='') as csvfile:
    ofile = csv.reader(csvfile, delimiter=',')
    next(ofile) # <-- skip the x,y,z header

    for line in ofile:
        f, *pts = line

        # these things are still strings (that's how they get stored in the file)
        # here we recast them to integer and floats
        frame_num = int(f)
        fpts = [float(p) for p in pts]
        coordinates = [fpts[0:3], fpts[3:6], fpts[6:9], fpts[9:12],
                       fpts[12:15], fpts[15:18], fpts[18:21], fpts[21:24],
                       fpts[24:27], fpts[27:30], fpts[30:33], fpts[33:36],
                       fpts[36:39], fpts[39:42],fpts[42:45], fpts[45:48],
                       fpts[48:51], fpts[51:54], fpts[54:57], fpts[57:60]]
                       

        bpy.context.scene.frame_set(frame_num)
        for ob, position in zip(empties, coordinates):
            ob.location = position
            ob.keyframe_insert(data_path="location", index=-1)

bpy.data.objects['rig'].select = True

target_file = 'hmr/output/bvh_animation/estimated_animation.bvh'

bpy.ops.export_anim.bvh(filepath=target_file)