I'm using parse_expr to parse student input to online quizzes. Since I
want them to be able to type in an answer as "xe^x" for x*exp(x) I have
tried to do the following transformations.
transformations=standard_transformations+(convert_xor, split_symbols,
implicit_multiplication)
The result is:
In [57]: parse_expr("xe^x", local_dict={'e': E},
transformations=transformations)
Out[57]: e**x*x
which means, the e was not mapped to E, as it should. If one makes the
multiplication explicit, and does not rely on split_symbols, then it works
correctly.
In [58]: parse_expr("x*e^x", local_dict={'e': E},
transformations=transformations)
Out[58]: x*exp(x)
The function
def _split_symbols(tokens, local_dict, global_dict)
completely ignores local_dict and global_dict. Should somehow
_split_symbols call auto_symbol on the new tokens it created?
Is there any way to get "xe^x" parsed as x*exp(x)? I suppose I could just
add a replace(Symbol('e'),E) after processing.
Duane
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