I want to automize my routine tasks such as changing 1 word in huge AutoCAD .DWG file with a lot of text blocks (objects in autocad). So, can I open it by Python? And how?
Your best bet here is to convert the file first into something like SVG or .dxf and go from there. It's not easy getting the data from a .dwg file in python.
You can make the conversion to SVG in python too using subprocess
and a command line convert tool like cad2svg.