How creating function to aplying image to object python

In other answer script not working:
(in Add a Texture to an Object using Python and Blender 2.8 answer not working, generate only black image and delete everything)

import bpy nazwa_tek="cyfry" plik_tek_gr="//grafiki/gr.png" tek =
bpy.data.materials.new(name=nazwa_tek) tek.use_nodes = True bsdf =
tek.node_tree.nodes["Principled BSDF"] texImage =
tek.node_tree.nodes.new('ShaderNodeTexImage') texImage.image =
bpy.data.images.load(plik_tek_gr)
#tek.diffuse_color = (1.0, 0.0, 1.0, 0.8) tek.node_tree.links.new(bsdf.inputs['Base Color'],
texImage.outputs['Color']) print("tekstura:=", tek)

def DodajTeksture(ob, nazwa="cyfry", plik_gr="//grafiki/gr.png"):
    global tek
    # Assign it to object
    if ob.data.materials:
      ob.data.materials[0] = tek
    else:
      ob.data.materials.append(tek)
    return

bpy.data.scenes["Scene"].render.image_settings.file_format = 'JPEG'
bpy.data.scenes["Scene"].render.filepath = './'
bpy.ops.render.render(animation = False) img = bpy.data.images[0]
img.save_render('wynik.jpg')
bpy.ops.wm.save_mainfile(filepath='bb.blend')

but how create a image texture? My texture are now procedural and do not have .image value. (I need image texture not procedural)

obrazek = bpy.ops.image.open(filepath="//file.png")
bpy.data.images["//file.png"].pack(as_png=True)

load image, but how aplying image for object named "Cube"?

How creating procedure in python

def appimage(obj, name_image, dx, dy)
   #applying image to object name obj staring from (dx,dy) in image
   return

create texture, add image to texture (one texture will be assign to some object) specifi region in image for this object. I have big texture for many objects. Only small region is for object. My image have transparent region (it schow diffuse color from bottom?).

appimage("Cube", "//file.png", 170, 200)