Fix energy histogram to properly handle default bucket ranges

tests/test_metric.py

@@ -99,7 +99,7 @@ def test_energy_histogram(
             cpu_histogram.labels = MagicMock(return_value=cpu_histogram)
             cpu_histogram.observe = MagicMock()
 
-    if histogram_metric.dram_histogram:
+    if histogram_metric.dram_histograms:
         for _dram_index, dram_histogram in histogram_metric.dram_histograms.items():
             dram_histogram.labels = MagicMock(return_value=dram_histogram)
             dram_histogram.observe = MagicMock()

zeus/metric.py

@@ -60,9 +60,9 @@ def __init__(
         gpu_indices: list,
         prometheus_url: str,
         job: str,
-        gpu_bucket_range: list[float] | None,
-        cpu_bucket_range: list[float] | None,
-        dram_bucket_range: list[float] | None,
+        gpu_bucket_range: list[float] | None = None,
+        cpu_bucket_range: list[float] | None = None,
+        dram_bucket_range: list[float] | None = None,
     ) -> None:
         """Initialize the EnergyHistogram class.
 
@@ -84,29 +84,41 @@ def __init__(
         Raises:
             ValueError: If any of the bucket ranges (GPU, CPU, DRAM) is an empty list.
         """
-        if not gpu_bucket_range:
+        self.gpu_bucket_range = (
+            [50.0, 100.0, 200.0, 500.0, 1000.0]
+            if gpu_bucket_range is None
+            else gpu_bucket_range
+        )
+        self.cpu_bucket_range = (
+            [10.0, 20.0, 50.0, 100.0, 200.0]
+            if cpu_bucket_range is None
+            else cpu_bucket_range
+        )
+        self.dram_bucket_range = (
+            [5.0, 10.0, 20.0, 50.0, 150.0]
+            if dram_bucket_range is None
+            else dram_bucket_range
+        )
+        self.cpu_indices = cpu_indices
+        self.gpu_indices = gpu_indices
+        self.prometheus_url = prometheus_url
+        self.job = job
+
+        self.registry = CollectorRegistry()
+
+        if gpu_bucket_range == []:
             raise ValueError(
                 "GPU bucket range cannot be empty. Please provide a valid range or omit the argument to use defaults."
             )
-        if not cpu_bucket_range:
+        if cpu_bucket_range == []:
             raise ValueError(
                 "CPU bucket range cannot be empty. Please provide a valid range or omit the argument to use defaults."
             )
-        if not dram_bucket_range:
+        if dram_bucket_range == []:
             raise ValueError(
                 "DRAM bucket range cannot be empty. Please provide a valid range or omit the argument to use defaults."
             )
 
-        self.gpu_bucket_range = gpu_bucket_range or [50.0, 100.0, 200.0, 500.0, 1000.0]
-        self.cpu_bucket_range = cpu_bucket_range or [10.0, 20.0, 50.0, 100.0, 200.0]
-        self.dram_bucket_range = dram_bucket_range or [5.0, 10.0, 20.0, 50.0, 150.0]
-        self.cpu_indices = cpu_indices
-        self.gpu_indices = gpu_indices
-        self.prometheus_url = prometheus_url
-        self.job = job
-
-        self.registry = CollectorRegistry()
-
         # Initialize GPU histograms
         self.gpu_histograms = {}
         if self.gpu_indices: