In : run test_temp.py
hello test temp world
In : run 'test_temp.py'
ERROR: File 'test_temp.py'.py not found.
In : run "test_temp.py"
ERROR: File "test_temp.py".py not found.
Consequently, it seems impossible to run a file whose path includes a space, or to run any file without converting its backslashes to forward slashes.
This makes cross-platform development messier.
Issues #95 and #378 also pertain to difficulty handling Windows paths.
Specifically, the problem is that the .parse_options() method used by most of the builtin %magics uses shlex.split() with posix=False on Windows. Arguably, this is not wrong. However, %run and other magics ought to postprocess arguments that are filenames on Windows to remove quotes.
Fixed by rkern's pull request #734