input_file = 'IUM_02.ipynb'
output_file = 'IUM_02.py'

import nbformat
from nbconvert import PythonExporter

with open(input_file, 'r', encoding='utf-8') as f:
    nb = nbformat.read(f, as_version=4)

exporter = PythonExporter()
source, meta = exporter.from_notebook_node(nb)

with open(output_file, 'w', encoding='utf-8') as f:
    f.write(source)