Provide 'how to upgrade' instructions, please?

[luciansmith]

I'm trying to maintain legacy code, which literally just broke because evalidate.evalidate is now gone. I don't know the code nearly well enough to tell how to update it; some sort of 'if you did X, do Y now' instructions would be fantastic.

Specifically, the code in question looks like:

    math_node = evalidate.evalidate(math,
                                    addnodes=VALID_MATH_EXPRESSION_NODES,
                                    funcs=MATHEMATICAL_FUNCTIONS.keys())
    compiled_math = compile(math_node, '<math>', 'eval')
    return compiled_math

Any hints appreciated!

[yaroslaff]

Easiest workaround is just to lock evalidate version to any before 2.0.0 (which I published just few hours ago), e.g. v1.1.0 has evalidate function.

But better to upgrade it:

#!/usr/bin/env python3

import evalidate

VALID_MATH_EXPRESSION_NODES = ['Call', 'Mult']
MATHEMATICAL_FUNCTIONS = ['int']

def pi():
    return 3.14 

model = evalidate.base_eval_model.clone()
model.nodes.extend(VALID_MATH_EXPRESSION_NODES)
model.allowed_functions.extend(MATHEMATICAL_FUNCTIONS)
model.imported_functions = dict(pi=pi)


def prepare(math):
    expr = evalidate.Expr(math, model=model)
    return expr.code

code = prepare('int(a) * 3 + pi() + 100')

# 139.14
print(eval(code, None, dict(a=12.34)))

[luciansmith]

Thank you! That was enough to figure it out, though I did have to change 'expr.code' to 'expr.node' to match the previous functionality. For future explorers:

    math_node = evalidate.evalidate(math,
                                    addnodes=VALID_MATH_EXPRESSION_NODES,
                                    funcs=MATHEMATICAL_FUNCTIONS.keys())

becomes:

    model = evalidate.base_eval_model.clone()
    model.nodes.extend(VALID_MATH_EXPRESSION_NODES)
    model.allowed_functions.extend(MATHEMATICAL_FUNCTIONS.keys())

    math_node = evalidate.Expr(math, model=model).node

If something like this could be added to the docs (for this and other functionality), I think that would help anyone else in the same boat.

[yaroslaff]

Attribute node is parsed AST tree, but not an python byte-code. Do you really need it (AST-tree)? If you need to eval(), then Expr.code is byte-code which would be evaluated very quickly (no need to call compile() to convert AST node to bytecode). Using code attribute can speed-up execution greatly (as demonstrated in benchmarks).

[luciansmith]

It's possible the downstream code could also be changed, but since 'evalidate' retuned a node, that's what the code expects--using 'code' gave me an error it took some time to track down. This is not time-sensitive code; the time it takes me as a programmer to update stuff is far far longer than the time spent executing it.