import {reticulate} | R Documentation |
Import a Python module
Description
Import the specified Python module, making it available for use from R.
Usage
import(module, as = NULL, convert = TRUE, delay_load = FALSE)
import_main(convert = TRUE, delay_load = FALSE)
import_builtins(convert = TRUE, delay_load = FALSE)
import_from_path(module, path = ".", convert = TRUE, delay_load = FALSE)
Arguments
module |
The name of the Python module. |
as |
An alias for module name (affects names of R classes). Note that this is an advanced parameter that should generally only be used in package development (since it affects the S3 name of the imported class and can therefore interfere with S3 method dispatching). |
convert |
Boolean; should Python objects be automatically converted
to their R equivalent? If set to |
delay_load |
Boolean; delay loading the module until it is first used?
When |
path |
The path from which the module should be imported. |
Value
An R object wrapping a Python module. Module attributes can be accessed
via the $
operator, or via py_get_attr()
.
Python Built-ins
Python's built-in functions (e.g. len()
) can be accessed via Python's
built-in module. Because the name of this module has changed between Python 2
and Python 3, we provide the function import_builtins()
to abstract over
that name change.
Delay Load
The delay_load
parameter accepts a variety of inputs. If you just need to
ensure your module is lazy-loaded (e.g. because you are a package author and
want to avoid initializing Python before the user has explicitly requested it),
then passing TRUE
is normally the right choice.
You can also provide a named list: "before_load"
, "on_load"
and
"on_error"
can be functions , which act as callbacks to be run when the
module is later loaded. "environment"
can be a character
vector of preferred python environment names to
search for and use. For example:
delay_load = list( # run before the module is loaded before_load = function() { ... } # run immediately after the module is loaded on_load = function() { ... } # run if an error occurs during module import on_error = function(error) { ... } environment = c("r-preferred-venv1", "r-preferred-venv2") )
Alternatively, if you supply only a single function, that will be treated as
an on_load
handler.
Import from Path
import_from_path()
can be used in you need to import a module from an arbitrary
filesystem path. This is most commonly used when importing modules bundled with an
R package – for example:
path <- system.file("python", package = <package>) reticulate::import_from_path(<module>, path = path, delay_load = TRUE)
Examples
## Not run:
main <- import_main()
sys <- import("sys")
## End(Not run)