validates schemespal input through frontend. this change only checks for empty string but maybe ascii pattern is better.
previously, backend will accept empty string and throw the following error:
File "/Users/home/Desktop/SchemesSG_v3/.venv/lib/python3.12/site-packages/numpy/lib/function_base.py", line 4835, in _quantile
previous = arr[previous_indexes]
~~~^^^^^^^^^^^^^^^^^^
IndexError: index -1 is out of bounds for axis 0 with size 0
fixes #24
validates schemespal input through frontend. this change only checks for empty string but maybe ascii pattern is better.
previously, backend will accept empty string and throw the following error: