PS C:UsersS3401DesktopNew folder> pyi-makespec filename.py
wrote C:UsersS3401DesktopNew folderfilename.spec
now run pyinstaller.py to build the executable
PS C:UsersS3401DesktopNew folder> pyinstaller .filename.spec
46 INFO: PyInstaller: 3.3.1
46 INFO: Python: 3.6.6
46 INFO: Platform: Windows-10-10.0.17134-SP0
47 INFO: UPX is not available.
Traceback (most recent call last):
  File "C:Program FilesPython36Scriptspyinstaller-script.py", line 11, in <module>
    load_entry_point('PyInstaller==3.3.1', 'console_scripts', 'pyinstaller')()
  File "c:program filespython36libsite-packagesPyInstaller__main__.py", line 94, in run
    run_build(pyi_config, spec_file, **vars(args))
  File "c:program filespython36libsite-packagesPyInstaller__main__.py", line 46, in run_build
    PyInstaller.building.build_main.main(pyi_config, spec_file, **kwargs)
  File "c:program filespython36libsite-packagesPyInstallerbuildingbuild_main.py", line 791, in main
    build(specfile, kw.get('distpath'), kw.get('workpath'), kw.get('clean_build'))
  File "c:program filespython36libsite-packagesPyInstallerbuildingbuild_main.py", line 737, in build
    exec(text, spec_namespace)
  File "<string>", line 16, in <module>
  File "c:program filespython36libsite-packagesPyInstallerbuildingbuild_main.py", line 162, in __init__
    raise ValueError("script '%s' not found" % script)
ValueError: script 'filename.py' not found