sympy

[scidam]

Since your code snippet is unformatted, I can just suppose what exactly code you ran.

def main():
    from sympy.abc import x, y
    code = """
    x + y + x
    """
    try:
        e = eval(code)
    except SyntaxError:
        print ("errores")
    print(e)

if __name__ == "__main__":
    main()

Error:
UnboundLocalError: local variable 'e' referenced before assignment

This is because the expression to be evaluated (the code string) includes spaces that causes
IndentationError. IndentationError, in turn, is subclass of SyntaxError, so, print(errors) is executed and variable e is not being assigned. This is why UnboundLocalError raised.