C++ API

The C++ API of bob.io.base allows users to leverage from automatic converters for classes in bob.io.base. To use the C API, clients should first, include the header file <bob.io.base/api.h> on their compilation units and then, make sure to call once import_bob_io_base() at their module instantiation, as explained at the Python manual.

Here is a dummy C example showing how to include the header and where to call the import function:

#include <bob.io.base/api.h>

PyMODINIT_FUNC initclient(void) {

  PyObject* m Py_InitModule("client", ClientMethods);

  if (!m) return;

  /* imports dependencies */
  if (import_bob_blitz() < 0) {
    PyErr_Print();
    PyErr_SetString(PyExc_ImportError, "cannot import extension");
    return 0;
  }

  if (import_bob_io_base() < 0) {
    PyErr_Print();
    PyErr_SetString(PyExc_ImportError, "cannot import extension");
    return 0;
  }

}

Generic Functions

int PyBobIo_AsTypenum(bob::core::array::ElementType et)

Converts the input Bob element type into a NPY_<TYPE> enumeration value. Returns NPY_NOTYPE in case of problems, and sets a RuntimeError.

PyObject *PyBobIo_TypeInfoAsTuple(const bob::core::array::typeinfo &ti)

Converts the bob::core::array::typeinfo& object into a new reference to a tuple with 3 elements:

[0]

The data type as a numpy.dtype object

[1]

The shape of the object, as a tuple of integers

[2]

The strides of the object, as a tuple of integers

Returns 0 in case of failure, or a new reference to the tuple described above in case of success.

int PyBobIo_FilenameConverter(PyObject *o, const char **b)

This function is meant to be used with PyArg_ParseTupleAndKeywords() family of functions in the Python C-API. It converts an arbitrary input object into a const char* If the input object is of type PyUnicodeObject (which is the default in Python3.x) the unicode code is properly decoded using PyUnicode_AsEncodedString() with encoding set to Py_FileSystemDefaultEncoding and errors set to "strict".

Objects which are not PyUnicodeObject are first coerced into a bytes/string before converting to the const char* object using PyObject_Bytes() (on Python3.x) and PyObject_Str() (on Python 2.x).

Returns 0 if an error is detected, 1 on success.

Note

Since version 2.2, this function converts into const char* directly. Before version 2.2, it was returning either PyBytesObject (Python 3) or PyStringObject (Python 2).

Bob File Support

type PyBobIoFileObject

The pythonic object representation for a bob::io::base::File object.

typedef struct {
  PyObject_HEAD
  boost::shared_ptr<bob::io::base::File> f;
} PyBobIoFileObject;

boost::shared_ptr<bob::io::base::File> f

A pointer to a file being read or written.

type PyBobIoFileIteratorObject

The pythonic object representation for an iterator over a bob::io::base::File object.

typedef struct {
  PyObject_HEAD
  PyBobIoFileObject* pyfile;
  Py_ssize_t curpos;
} PyBobIoFileIteratorObject;

PyBobIoFileObject *pyfile

A pointer to the pythonic representation of a file.

Py_ssize_t curpos

The current position at the file being pointed to.

Bob HDF5 Support

type PyBobIoHDF5FileObject

The pythonic object representation for a bob::io::base::HDF5File object.

typedef struct {
  PyObject_HEAD
  boost::shared_ptr<bob::io::base::HDF5File> f;
} PyBobIoHDF5FileObject;

boost::shared_ptr<bob::io::base::HDF5File> f

A pointer to a Bob object being used to read/write data into an HDF5 file.

int PyBobIoHDF5File_Check(PyObject *o)

Checks if the input object o is a PyBobIoHDF5FileObject. Returns 1 if it is, and 0 otherwise.

int PyBobIoHDF5File_Converter(PyObject *o, PyBobIoHDF5FileObject **a)

This function is meant to be used with PyArg_ParseTupleAndKeywords() family of functions in the Python C-API. It checks the input object to be of type PyBobIoHDF5FileObject and sets a new reference to it (in *a) if it is the case. Returns 0 in case of failure, 1 in case of success.