Can't call some python callables

Hi,

Should R functions converted to python still be callable from R?

library(reticulate)
fn <- r_to_py(function(x) x)
try(fn(1)) # should this succeed?
#> Error in fn(1) : could not find function "fn"

Calling py_to_r enables calling again, but doesn’t change the class or printed output.

fn
#> <function make_python_function.<locals>.python_function at 0x7f243344aef0>
class(fn)
#> [1] "python.builtin.function" "python.builtin.object"
fn <- py_to_r(fn)
fn
#> <function make_python_function.<locals>.python_function at 0x7f243344aef0>
class(fn)
#> [1] "python.builtin.function" "python.builtin.object"
fn(1)
#> 1.0

(Changing the value of convert seems to make no difference.)

This comment and the extensive use of as.environment suggests that maybe the intent is for all python callables to be callable from R and this is a bug?

It would be very convenient if all python callables are always directly callable from R without needing to go though py_call.

^{Created on 2021-07-02 by the reprex package (v2.0.0)}

Start with R/python.R around the referenced line 220 and trace how r_to_py creates Python callables, including the use of as.environment. Reproduce the issue's fn(1) example and compare it with py_to_r and py_call; done means a callable returned by r_to_py can be called directly from R as described.