I have a list of functions as strings:
["y + x + 3", "x**2 + y**2 - 17"] # 2 functions in list
I have a list of Sympy Symbol objects (basically variables) whos .name attribute cooresponds to the variables names in the function strings:
[Symbol(x), Symbol(y)]
# list element 0's .name attribute is "x"
I found that Python have a neat function called eval() which can evaluate strings, for example:
x = 1
eval("x + 3") # Result should be 4
Basically this is what I want to do with my functions strings. However, since this is a dynamic implementation I don't have variables defined on a line above eval() in my program, they are in a list instead. For example, in the example above x is defined as 1, so then the eval() function can use it.
But I have my variables in a list, not defined as a variable in the scope of my function. How could I use the eval() function and utilize my list of variables?
eval takes local variables as third argument(reference),
so you can do this:
from sympy import Symbol
zs = [Symbol('x'), Symbol('y')]
eval('x+y', None, dict([z.name, z] for z in zs))
However, maybe you should use parse_expr which is part of SymPy.
from sympy import Symbol
from sympy.parsing.sympy_parser import parse_expr
zs = [Symbol('x'), Symbol('y')]
parse_expr('x+y', local_dict=dict([z.name, z] for z in zs))