does not work properly when opened using subprocess.call(), subprocess.run() or similar commands in python script

[tb-dhk]

whenever i use subprocess.call(['termgraph', 'stats.dat']) or other similar commands in a python script, i always get this error:

Traceback (most recent call last):
  File "/home/user/.local/bin/termgraph", line 8, in <module>
    sys.exit(main())
  File "/home/user/.local/lib/python3.10/site-packages/termgraph/termgraph.py", line 133, in main
    _, labels, data, colors = read_data(args)
  File "/home/user/.local/lib/python3.10/site-packages/termgraph/termgraph.py", line 712, in read_data
    colors = check_data(labels, data, args)
  File "/home/user/.local/lib/python3.10/site-packages/termgraph/termgraph.py", line 569, in check_data
    len_categories = len(data[0])
IndexError: list index out of range

however, these commands work outside python scripts like in the python shell or just the command line. is there any way i can allow them to run in python scripts as well?