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RPy provides three functions for customizing the input and output from the R interpreter.
In versions 0.1 and 0.2, the input/output from/to R was connected
to the C stdin/stdout, which don't necessarily coincides with the
Python sys.stdin/sys.stdout. These was noticeable if you run those
versions over IDLE or other IDE (probably, you don't see the output of
r.print_(5)
). Now, the R input/output is connected, by default, to
the Python streams. But you can insert your own functions for reading,
writing and displaying files.
get_rpy_input()
set_rpy_input(f)
The parameter for set_rpy_input
must be a function with signature
f(prompt, size)
. The parameter prompt is a string to be
displayed and size is an integer which denotes the maximum length of
the input buffer.
get_rpy_output()
set_rpy_output(f)
The parameter for set_rpy_output
must be a function with
signature f(s)
, where s is the string to be displayed.
get_rpy_showfiles()
set_rpy_showfiles(f)
help
command.
The parameter for set_rpy_showfiles
must be a function with
signature f(files, headers, title, delete)
. Parameters
files and headers are lists of filenames and strings,
respectively, to be displayed sequentially. Parameter title is the
overall title and parameter delete signals whether the files
should be deleted after displaying.
The default values for the input/output/showfiles functions are in the io module. That is, when RPy is imported, the following instructions are executed:
import io set_rpy_input(io.rpy_input) set_rpy_output(io.rpy_output) set_rpy_showfiles(io.rpy_showfiles)
For input and output, the functions io.rpy_input
and
io.rpy_output
just use the sys.stdin and sys.stdout streams of
Python. For displaying files, the io module provides two
functions: io.showfiles_common
and io.showfiles_tty
, and
the default io.rpy_showfiles
is an alias for the former. Function
io.showfiles_common
displays the files using the
io.rpy_output
function, while function io.showfiles_tty
displays the files using a pager (namely less
, you may need to
customize it).
help
command is always displayed on
a separate window. The R event loop (see Miscellaneous) must be
running for the window to be functional.