Return event fields by field name

Since a field may be present both in an event and its stream's scope,
this returns a list which contains all the fields by the name. The
examples are also changed to match this new API.

Signed-off-by: Xiaona Han <xiaonahappy13@163.com>
Acked-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Remove the unnecessary underscore prefix

When getting the fields of an event by name, it is not necessary
to add an underscore prefix. This removes the underscore prefix of
the field names in the examples.

Signed-off-by: Xiaona Han <xiaonahappy13@163.com>
Acked-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Support getting the value of enums

Use 'get_enum_str' to get the string matching the current enumeration.

Signed-off-by: Xiaona Han <xiaonahappy13@163.com>
Acked-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Add a generic get_value() implementation

Use get_value to get a field's value. Currently it does not support
compound types. Also it does not support floating point, since getting
a float's value is not implemented in babeltrace now.

Edit by Jérémie Galarneau: Arrays' value should not be returned using
get_char_array(). Implemented get_array_element_at() which returns a
Definition object corresponding to the array's element.

Exposed the bt_array_index function in the Python bindings

Signed-off-by: Xiaona Han <xiaonahappy13@163.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Support for the sequence type

Add support for getting a sequence's value in the python binding.

Signed-off-by: Xiaona Han <xiaonahappy13@163.com>
Acked-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Add a python bindings sequence test

This example is meant to test whether we can get a sequence's values in
the python binding well or not. It is used in conjunction with the
sequence test in the dir tests/ctf-traces/succeed/sequence.

Signed-off-by: Xiaona Han <xiaonahappy13@163.com>
Acked-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Remove Python 2 specific examples

These examples rely on the cairoplot module which is not compatible with
Python 3.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>