R/pyr6.r
In mkoohafkan/pysockr: Execute Python from R
#' Socket-based Interface for Python Processes
#'
#' A simple socket-based interface to Python. Provides a basic
#' Python server script and R6 class for interacting with a
#' Python process.
#' @name expyr-package
#' @aliases expyr
#' @docType package
NULL
#' Python Environment
#'
#' The Python Environment Class. Provides an interface to a Python process.
#'
#'
#' @section Usage:
#' \preformatted{py = PythonEnv$new(port, path)
#'
#' py$start()
#'
#' py$running
#' py$pid
#' py$path (py$path <-)
#' py$host (py$host <-)
#' py$port (py$port <-)
#' py$timeout (py$timeout <-)
#'
#' py$exec(..., file = NULL)
#' py$set(...)
#' py$get(varname)
#'
#' py$stop(force = FALSE)
#'
#' print(py)
#' }
#'
#' @section Arguments:
#' \code{port} The port to use for communication with Python.
#'
#' \code{path} The path to the Python executable.
#'
#' \code{varname} The name of a Python variable to bring into R.
#'
#' \code{...} Commands to run or named variables to set in the Python process.
#'
#' \code{file} File containing Python code to execute.
#'
#' \code{force} If \code{TRUE}, force the Python process to terminate
#' using a system call.
#'
#' @section Methods:
#' \code{$new()} Initialize a Python interface. The Python process is not
#' started automatically.
#'
#' \code{$path} Set or get the path to the Python executable. The path
#' cannot be changed while the Python process is running.
#'
#' \code{$host} Set or get the host address of the Python connection.
#' Default is \code{'localhost'}. The host cannot be changed while the
#' Python process is running.
#'
#' \code{$port} Set or get the port of the Python interface. The port
#' cannot be changed while the Python process is running.
#'
#' \code{$timeout} Set or get the timeout for receiving messages from
#' Python. Default is 60 seconds.
#'
#' \code{$start()} Start the Python process. The Python process runs
#' asynchronously.
#'
#' \code{$running} Check if the Python process is running.
#'
#' \code{$pid} Get the Process ID of the Python interface. Useful for
#' diagnosing problems.
#'
#' \code{$set()} Set variables in the Python process. R variables
#' are encoded into JSON format, sent to the Python process as text,
#' and decoded into variables on the Python side.
#'
#' \code{$get()} Get a variable from the Python process. Python
#' variables are encoded into JSON format, sent to R as text,
#' and decoded into variables on the R side.
#'
#' \code{$exec()} Execute the specified Python
#' commands and invisibly return printed Python output (if any).
#' Alternatively, the \code{file} argument can be used to specify
#' a file containing Python code. Note that there will be no return
#' value unless an explicit Python \code{print} statement is executed.
#'
#' \code{$stop()} Stop the Python process by sending a request to the
#' Python process. If \code{force = TRUE}, the process will be
#' terminated using a system call instead.
#'
#' \code{print(py)} Show some information about the
#' Python process on the screen, whether it is running and its process id,
#' etc.
#'
#' @name PythonEnv
#' @examples
#' \dontrun{
#' pypath = Sys.which('python')
#' py = PythonEnv$new(path = pypath, port = 6011, host = "127.0.0.1")
#' py$start()
#' py$running
#' py$set(a = 5)
#' py$get('a')
#' py$stop(force = TRUE)
#' }
NULL
#' @export
PythonEnv = R6::R6Class("PythonEnv", cloneable = FALSE,
private = list(
currentpid = NULL,
currentport = NULL,
currentpath = NULL,
currenthost = NULL,
currenttimeout = NULL,
version = NULL,
isrunning = NULL,
socket = function() {
socketConnection(host = self$host, port = self$port,
open = 'r+', blocking = TRUE, server = FALSE,
timeout = self$timeout, encoding = "UTF-8")
}
),
public = list(
print = function(...) {
cat("Python ", private$version, "\n", sep = "")
cat("(", self$path, ")\n", sep = "")
if (self$running)
cat("Listening on ", self$host, ":", self$port,
" (Process ID: ", self$pid, ")\n", sep = "")
else
cat("Process not running")
},
initialize = function(path, port, host = "localhost") {
private$currentpath = as.character(path)
private$currenthost = as.character(host)
private$currenttimeout = 60
private$currentport = as.integer(port)
private$version = "(version unknown)"
private$isrunning = FALSE
invisible(self)
},
finalize = function() {
if (self$running)
self$stop(force = TRUE)
},
start = function() {
if (self$running) {
message("The Python process is already running")
return(invisible(self))
}
if (is.na(self$port) || length(self$port) == 0L) {
stop("Invalid port specified", call. = FALSE)
} else if (self$port < 1024L) {
warning("Using port numbers below 1024 is not recommended")
}
if(system2(self$path, args = "--version", stdout = FALSE) != 0L)
stop("Invalid path specified", call. = FALSE)
fpath = system.file("py-src/expyr.py", package = "expyr")
system2(self$path, wait = FALSE,
args = c(shQuote(fpath), self$port, self$host))
# check if it's running
s = private$socket()
on.exit(close(s))
writeLines('print("RUNNING")', s)
res = readLines(s, warn = FALSE)
if (length(res) < 1L)
stop("Connection to Python could not be established", call. = FALSE)
else
private$isrunning = TRUE
# get pid
private$currentpid = as.integer(self$exec('print(OS.getpid())'))
# get version
private$version = self$exec('print(SYS.version)')
self
},
stop = function(force = FALSE) {
if (!self$running) {
message("The Python process is not running")
} else if (force) {
tools::pskill(self$pid)
message("Python process ", self$pid, " was terminated", sep = "")
private$isrunning = FALSE
} else {
res = self$exec("quit")
if (res != "QUIT")
stop("The Python process could not be shut down normally")
private$isrunning = FALSE
message("Python process ", self$pid, " was terminated", sep = "")
}
invisible(self)
},
exec = function(..., file = NULL) {
if (!self$running)
stop("The Python process is not running", call. = FALSE)
if(!is.null(file))
code = paste(readLines(normalizePath(file, mustWork = TRUE)),
collapse = "\n")
else
code = paste(list(...), collapse = "\n")
s = private$socket()
on.exit(close(s))
writeLines(code, s)
res = readLines(s, warn = FALSE)
if(length(res) > 0)
if(res[1] == "expyr-error")
stop("Python returned an error\n",
paste(tail(res, -1), collapse = "\n"), call. = FALSE)
invisible(res)
},
get = function(varname) {
if (!self$running)
stop("The Python process is not running", call. = FALSE)
msg = sprintf("print(EXPYR_JSON_DUMPS(%s))", varname)
rjson::fromJSON(self$exec(msg))
},
set = function(...) {
if (!self$running)
stop("The Python process is not running", call. = FALSE)
dots = list(...)
if (!all(grepl("^[_a-zA-Z][0-9a-zA-Z]*$", names(dots))))
stop("Invalid Python variable name")
jdots = rjson::toJSON(dots)
self$exec(sprintf("globals().update(%s)", jdots))
}
),
active = list(
running = function() {
private$isrunning
},
port = function(value) {
if (missing(value))
return(private$currentport)
if (self$running)
stop("Cannot update the port while the Python process is running",
call. = FALSE)
private$currentport = as.integer(value)
},
host = function(value) {
if (missing(value))
return(private$currenthost)
if (self$running)
stop("Cannot update the host while the Python process is running",
call. = FALSE)
private$currenthost = value
},
path = function(value) {
if (missing(value))
return(private$currentpath)
if (self$running)
stop("Cannot update the path while the Python process is running",
call. = FALSE)
private$currentpath = value
},
pid = function() {
private$currentpid
},
timeout = function(value) {
if (missing(value))
return(private$currenttimeout)
private$currenttimeout = value
}
)
)
mkoohafkan/pysockr documentation built on May 6, 2019, 10:37 a.m.
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
#' Socket-based Interface for Python Processes
#'
#' A simple socket-based interface to Python. Provides a basic
#' Python server script and R6 class for interacting with a
#' Python process.
#' @name expyr-package
#' @aliases expyr
#' @docType package
NULL
#' Python Environment
#'
#' The Python Environment Class. Provides an interface to a Python process.
#'
#'
#' @section Usage:
#' \preformatted{py = PythonEnv$new(port, path)
#'
#' py$start()
#'
#' py$running
#' py$pid
#' py$path (py$path <-)
#' py$host (py$host <-)
#' py$port (py$port <-)
#' py$timeout (py$timeout <-)
#'
#' py$exec(..., file = NULL)
#' py$set(...)
#' py$get(varname)
#'
#' py$stop(force = FALSE)
#'
#' print(py)
#' }
#'
#' @section Arguments:
#' \code{port} The port to use for communication with Python.
#'
#' \code{path} The path to the Python executable.
#'
#' \code{varname} The name of a Python variable to bring into R.
#'
#' \code{...} Commands to run or named variables to set in the Python process.
#'
#' \code{file} File containing Python code to execute.
#'
#' \code{force} If \code{TRUE}, force the Python process to terminate
#' using a system call.
#'
#' @section Methods:
#' \code{$new()} Initialize a Python interface. The Python process is not
#' started automatically.
#'
#' \code{$path} Set or get the path to the Python executable. The path
#' cannot be changed while the Python process is running.
#'
#' \code{$host} Set or get the host address of the Python connection.
#' Default is \code{'localhost'}. The host cannot be changed while the
#' Python process is running.
#'
#' \code{$port} Set or get the port of the Python interface. The port
#' cannot be changed while the Python process is running.
#'
#' \code{$timeout} Set or get the timeout for receiving messages from
#' Python. Default is 60 seconds.
#'
#' \code{$start()} Start the Python process. The Python process runs
#' asynchronously.
#'
#' \code{$running} Check if the Python process is running.
#'
#' \code{$pid} Get the Process ID of the Python interface. Useful for
#' diagnosing problems.
#'
#' \code{$set()} Set variables in the Python process. R variables
#' are encoded into JSON format, sent to the Python process as text,
#' and decoded into variables on the Python side.
#'
#' \code{$get()} Get a variable from the Python process. Python
#' variables are encoded into JSON format, sent to R as text,
#' and decoded into variables on the R side.
#'
#' \code{$exec()} Execute the specified Python
#' commands and invisibly return printed Python output (if any).
#' Alternatively, the \code{file} argument can be used to specify
#' a file containing Python code. Note that there will be no return
#' value unless an explicit Python \code{print} statement is executed.
#'
#' \code{$stop()} Stop the Python process by sending a request to the
#' Python process. If \code{force = TRUE}, the process will be
#' terminated using a system call instead.
#'
#' \code{print(py)} Show some information about the
#' Python process on the screen, whether it is running and its process id,
#' etc.
#'
#' @name PythonEnv
#' @examples
#' \dontrun{
#' pypath = Sys.which('python')
#' py = PythonEnv$new(path = pypath, port = 6011, host = "127.0.0.1")
#' py$start()
#' py$running
#' py$set(a = 5)
#' py$get('a')
#' py$stop(force = TRUE)
#' }
NULL
#' @export
PythonEnv = R6::R6Class("PythonEnv", cloneable = FALSE,
private = list(
currentpid = NULL,
currentport = NULL,
currentpath = NULL,
currenthost = NULL,
currenttimeout = NULL,
version = NULL,
isrunning = NULL,
socket = function() {
socketConnection(host = self$host, port = self$port,
open = 'r+', blocking = TRUE, server = FALSE,
timeout = self$timeout, encoding = "UTF-8")
}
),
public = list(
print = function(...) {
cat("Python ", private$version, "\n", sep = "")
cat("(", self$path, ")\n", sep = "")
if (self$running)
cat("Listening on ", self$host, ":", self$port,
" (Process ID: ", self$pid, ")\n", sep = "")
else
cat("Process not running")
},
initialize = function(path, port, host = "localhost") {
private$currentpath = as.character(path)
private$currenthost = as.character(host)
private$currenttimeout = 60
private$currentport = as.integer(port)
private$version = "(version unknown)"
private$isrunning = FALSE
invisible(self)
},
finalize = function() {
if (self$running)
self$stop(force = TRUE)
},
start = function() {
if (self$running) {
message("The Python process is already running")
return(invisible(self))
}
if (is.na(self$port) || length(self$port) == 0L) {
stop("Invalid port specified", call. = FALSE)
} else if (self$port < 1024L) {
warning("Using port numbers below 1024 is not recommended")
}
if(system2(self$path, args = "--version", stdout = FALSE) != 0L)
stop("Invalid path specified", call. = FALSE)
fpath = system.file("py-src/expyr.py", package = "expyr")
system2(self$path, wait = FALSE,
args = c(shQuote(fpath), self$port, self$host))
# check if it's running
s = private$socket()
on.exit(close(s))
writeLines('print("RUNNING")', s)
res = readLines(s, warn = FALSE)
if (length(res) < 1L)
stop("Connection to Python could not be established", call. = FALSE)
else
private$isrunning = TRUE
# get pid
private$currentpid = as.integer(self$exec('print(OS.getpid())'))
# get version
private$version = self$exec('print(SYS.version)')
self
},
stop = function(force = FALSE) {
if (!self$running) {
message("The Python process is not running")
} else if (force) {
tools::pskill(self$pid)
message("Python process ", self$pid, " was terminated", sep = "")
private$isrunning = FALSE
} else {
res = self$exec("quit")
if (res != "QUIT")
stop("The Python process could not be shut down normally")
private$isrunning = FALSE
message("Python process ", self$pid, " was terminated", sep = "")
}
invisible(self)
},
exec = function(..., file = NULL) {
if (!self$running)
stop("The Python process is not running", call. = FALSE)
if(!is.null(file))
code = paste(readLines(normalizePath(file, mustWork = TRUE)),
collapse = "\n")
else
code = paste(list(...), collapse = "\n")
s = private$socket()
on.exit(close(s))
writeLines(code, s)
res = readLines(s, warn = FALSE)
if(length(res) > 0)
if(res[1] == "expyr-error")
stop("Python returned an error\n",
paste(tail(res, -1), collapse = "\n"), call. = FALSE)
invisible(res)
},
get = function(varname) {
if (!self$running)
stop("The Python process is not running", call. = FALSE)
msg = sprintf("print(EXPYR_JSON_DUMPS(%s))", varname)
rjson::fromJSON(self$exec(msg))
},
set = function(...) {
if (!self$running)
stop("The Python process is not running", call. = FALSE)
dots = list(...)
if (!all(grepl("^[_a-zA-Z][0-9a-zA-Z]*$", names(dots))))
stop("Invalid Python variable name")
jdots = rjson::toJSON(dots)
self$exec(sprintf("globals().update(%s)", jdots))
}
),
active = list(
running = function() {
private$isrunning
},
port = function(value) {
if (missing(value))
return(private$currentport)
if (self$running)
stop("Cannot update the port while the Python process is running",
call. = FALSE)
private$currentport = as.integer(value)
},
host = function(value) {
if (missing(value))
return(private$currenthost)
if (self$running)
stop("Cannot update the host while the Python process is running",
call. = FALSE)
private$currenthost = value
},
path = function(value) {
if (missing(value))
return(private$currentpath)
if (self$running)
stop("Cannot update the path while the Python process is running",
call. = FALSE)
private$currentpath = value
},
pid = function() {
private$currentpid
},
timeout = function(value) {
if (missing(value))
return(private$currenttimeout)
private$currenttimeout = value
}
)
)
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
Embedding an R snippet on your website
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.