Parser does not cover all cases

[light-weaver]

math_json_parser/math_json_parser/parser_polars.py

Line 98 in 4f40955

elif textlist not in self.operator_map:

You cover cases where the input is either a list or not a list. Then you assume that if the input is not a list, it must be a column name. That may not be true. The input may just be a constant ("pi", "e", "10.5", etc.). Handle that case as well.