From c79706ff4ce591df2151db5504d3c224f3c9965f Mon Sep 17 00:00:00 2001 From: Andreas Sandberg Date: Mon, 27 Feb 2017 13:17:51 +0000 Subject: ext: Add pybind rev f4b81b3 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Change-Id: I52e4fc9ebf2f59da57d8cf8f3e37cc79598c2f5f Signed-off-by: Andreas Sandberg Reviewed-by: Andreas Hansson Reviewed-by: Curtis Dunham Reviewed-on: https://gem5-review.googlesource.com/2229 Reviewed-by: Tony Gutierrez Reviewed-by: Jason Lowe-Power Reviewed-by: Pierre-Yves PĂ©neau --- ext/pybind11/docs/advanced/pycpp/utilities.rst | 57 ++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 ext/pybind11/docs/advanced/pycpp/utilities.rst (limited to 'ext/pybind11/docs/advanced/pycpp/utilities.rst') diff --git a/ext/pybind11/docs/advanced/pycpp/utilities.rst b/ext/pybind11/docs/advanced/pycpp/utilities.rst new file mode 100644 index 000000000..ba0dbef88 --- /dev/null +++ b/ext/pybind11/docs/advanced/pycpp/utilities.rst @@ -0,0 +1,57 @@ +Utilities +######### + +Using Python's print function in C++ +==================================== + +The usual way to write output in C++ is using ``std::cout`` while in Python one +would use ``print``. Since these methods use different buffers, mixing them can +lead to output order issues. To resolve this, pybind11 modules can use the +:func:`py::print` function which writes to Python's ``sys.stdout`` for consistency. + +Python's ``print`` function is replicated in the C++ API including optional +keyword arguments ``sep``, ``end``, ``file``, ``flush``. Everything works as +expected in Python: + +.. code-block:: cpp + + py::print(1, 2.0, "three"); // 1 2.0 three + py::print(1, 2.0, "three", "sep"_a="-"); // 1-2.0-three + + auto args = py::make_tuple("unpacked", true); + py::print("->", *args, "end"_a="<-"); // -> unpacked True <- + +Evaluating Python expressions from strings and files +==================================================== + +pybind11 provides the :func:`eval` and :func:`eval_file` functions to evaluate +Python expressions and statements. The following example illustrates how they +can be used. + +Both functions accept a template parameter that describes how the argument +should be interpreted. Possible choices include ``eval_expr`` (isolated +expression), ``eval_single_statement`` (a single statement, return value is +always ``none``), and ``eval_statements`` (sequence of statements, return value +is always ``none``). + +.. code-block:: cpp + + // At beginning of file + #include + + ... + + // Evaluate in scope of main module + py::object scope = py::module::import("__main__").attr("__dict__"); + + // Evaluate an isolated expression + int result = py::eval("my_variable + 10", scope).cast(); + + // Evaluate a sequence of statements + py::eval( + "print('Hello')\n" + "print('world!');", + scope); + + // Evaluate the statements in an separate Python file on disk + py::eval_file("script.py", scope); -- cgit v1.2.3