#955: sensors_battery() / linux: implement secsleft

3 files changed, 22 insertions, 7 deletions

diff --git a/docs/index.rst b/docs/index.rst
index 8db5b111..52424b39 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -629,7 +629,18 @@ Sensors
     may also be :data:`psutil.POWER_TIME_UNKNOWN <psutil.POWER_TIME_UNKNOWN>`
     or :data:`psutil.POWER_TIME_UNLIMITED <psutil.POWER_TIME_UNLIMITED>`.
 
-  If no battery is installed this function will return ``None``.
+  If no battery is installed this function will return ``None``. Example::
+
+    >>> def secs2hours(secs):
+    ...     m, s = divmod(secs, 60)
+    ...     h, m = divmod(m, 60)
+    ...     return "%d:%02d:%02d" % (h, m, s)
+    ...
+    >>> batt = psutil.sensors_battery()
+    >>> batt
+    sbattery(percent=93, secsleft=16628)
+    >>> print("charge = %s%%, time left = %s" % (batt.percent, secs2hours(batt.secsleft)))
+    charge = 93%, time left = 4:37:08
 
   Availability: Linux, Windows
 
diff --git a/psutil/_pslinux.py b/psutil/_pslinux.py
index 0fba0fa6..fff77aab 100644
--- a/psutil/_pslinux.py
+++ b/psutil/_pslinux.py
@@ -1069,13 +1069,11 @@ def sensors_battery():
     if not os.path.exists(root.rstrip('/')):
         return None
 
-    # TODO: figure out the algorithm to calculate residual time.
-    # energy_now = int(cat(root + "energy_now"))
-    # power_now = int(cat(root + "power_now"))
-    # energy_full = int(cat(root + "energy_full"))
-    # secsleft = 3600 * energy_now / power_now
+    energy_now = int(cat(root + "energy_now"))
+    power_now = int(cat(root + "power_now"))
     percent = int(cat(root + "capacity"))
-    return _common.sbattery(percent, 0)
+    secsleft = int(energy_now / power_now * 3600)
+    return _common.sbattery(percent, secsleft)
 
 
 # =====================================================================
diff --git a/psutil/tests/test_linux.py b/psutil/tests/test_linux.py
index 37352ecf..54d5e251 100755
--- a/psutil/tests/test_linux.py
+++ b/psutil/tests/test_linux.py
@@ -1024,6 +1024,12 @@ class TestMisc(unittest.TestCase):
         finally:
             t.stop()
 
+    def test_sensors_battery_percent(self):
+        out = sh("acpi -b")
+        acpi_value = int(out.split(",")[1].strip().replace('%', ''))
+        psutil_value = psutil.sensors_battery().percent
+        self.assertAlmostEqual(acpi_value, psutil_value, delta=1)
+
 
 # =====================================================================
 # test process