win32com.client.Dispatch

import win32com.client  # pywin32
import os

psApp = win32com.client.Dispatch("Photoshop.Application")
psApp.Open('test.psd')
doc = psApp.Application.ActiveDocument
layer_facts = doc.ArtLayers["номер"]
text_of_layer = layer_facts.TextItem
text_of_layer.contents = "This is an example of a new text."