[PATCH v5 20/21] perf python: Add __str__ and __repr__ functions to evsel

[Ian Rogers <irogers@google.com>]

This allows evsel to be shown in the REPL like:
```
Python 3.11.9 (main, Jun 19 2024, 00:38:48) [GCC 13.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.path.insert(0, '/tmp/perf/python')
>>> import perf
>>> x=perf.parse_events('cycles,data_read')
>>> print(x)
evlist([cycles,uncore_imc_free_running_0/data_read/,uncore_imc_free_running_1/data_read/])
>>> x[0]
evsel(cycles)
>>> x[1]
evsel(uncore_imc_free_running_0/data_read/)
>>> x[2]
evsel(uncore_imc_free_running_1/data_read/)
```

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/python.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index a71bad3418da..0d71ec673aa3 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -781,6 +781,17 @@ static PyObject *pyrf_evsel__open(struct pyrf_evsel *pevsel,
 	return Py_None;
 }
 
+static PyObject *pyrf_evsel__str(PyObject *self)
+{
+	struct pyrf_evsel *pevsel = (void *)self;
+	struct evsel *evsel = &pevsel->evsel;
+
+	if (!evsel->pmu)
+		return PyUnicode_FromFormat("evsel(%s)", evsel__name(evsel));
+
+	return PyUnicode_FromFormat("evsel(%s/%s/)", evsel->pmu->name, evsel__name(evsel));
+}
+
 static PyMethodDef pyrf_evsel__methods[] = {
 	{
 		.ml_name  = "open",
@@ -802,6 +813,8 @@ static PyTypeObject pyrf_evsel__type = {
 	.tp_doc		= pyrf_evsel__doc,
 	.tp_methods	= pyrf_evsel__methods,
 	.tp_init	= (initproc)pyrf_evsel__init,
+	.tp_str         = pyrf_evsel__str,
+	.tp_repr        = pyrf_evsel__str,
 };
 
 static int pyrf_evsel__setup_types(void)
-- 
2.47.0.163.g1226f6d8fa-goog