log_metric: Make timestamp optional. (#352)

Default to not include timestamp.
Closes #233

src/dvclive/live.py

@@ -153,7 +153,9 @@ def set_step(self, step: int) -> None:
     def next_step(self):
         self.set_step(self.get_step() + 1)
 
-    def log_metric(self, name: str, val: Union[int, float]):
+    def log_metric(
+        self, name: str, val: Union[int, float], timestamp: bool = False
+    ):
         if not Metric.could_log(val):
             raise InvalidDataTypeError(name, type(val))
 
@@ -164,7 +166,7 @@ def log_metric(self, name: str, val: Union[int, float]):
             self._metrics[name] = data
 
         data.step = self.get_step()
-        data.dump(val)
+        data.dump(val, timestamp=timestamp)
 
         self.summary = nested_update(self.summary, data.to_summary(val))
         self.make_summary()

src/dvclive/plots/base.py

@@ -1,6 +1,5 @@
 import abc
 from pathlib import Path
-from typing import Optional
 
 from dvclive.error import DataAlreadyLoggedError
 
@@ -9,10 +8,10 @@ class Data(abc.ABC):
     def __init__(self, name: str, output_folder: str) -> None:
         self.name = name
         self.output_folder: Path = Path(output_folder) / self.subfolder
-        self._step: Optional[int] = None
+        self._step: int = -1
 
     @property
-    def step(self) -> Optional[int]:
+    def step(self) -> int:
         return self._step
 
     @step.setter

src/dvclive/plots/metric.py

@@ -1,7 +1,6 @@
 import csv
 import os
 import time
-from collections import OrderedDict
 from pathlib import Path
 
 from dvclive.utils import nested_set
@@ -30,18 +29,20 @@ def output_path(self) -> Path:
         return _path
 
     def dump(self, val, **kwargs) -> None:
-        ts = int(time.time() * 1000)
-        d = OrderedDict(
-            [("timestamp", ts), ("step", self.step), (self.name, val)]
-        )
+        row = {}
+        if kwargs.get("timestamp", False):
+            row["timestamp"] = int(time.time() * 1000)
+        row["step"] = self.step
+        row[self.name] = val
+
         existed = self.output_path.exists()
         with open(self.output_path, "a", encoding="utf-8", newline="") as fobj:
             writer = csv.DictWriter(
                 fobj, d.keys(), delimiter="\t", lineterminator="\n"
             )
             if not existed:
                 writer.writeheader()
-            writer.writerow(d)
+            writer.writerow(row)
 
     def to_summary(self, val):
         d = {}

tests/test_main.py

@@ -355,3 +355,14 @@ def test_make_summary_without_calling_log(tmp_dir):
     }
     log_file = tmp_dir / dvclive.plots_dir / Metric.subfolder / "foo.tsv"
     assert not log_file.exists()
+
+
+@pytest.mark.parametrize("timestamp", (True, False))
+def test_log_metric_timestamp(timestamp):
+    live = Live()
+    live.log_metric("foo", 1.0, timestamp=timestamp)
+    live.next_step()
+
+    history, _ = parse_metrics(live)
+    logged = next(iter(history.values()))
+    assert ("timestamp" in logged[0]) == timestamp

tests/test_report.py

@@ -52,13 +52,11 @@ def test_get_renderers(tmp_dir, mocker):
             "foo/bar": "0",
             "rev": "workspace",
             "step": "0",
-            "timestamp": mocker.ANY,
         },
         {
             "foo/bar": "1",
             "rev": "workspace",
             "step": "1",
-            "timestamp": mocker.ANY,
         },
     ]
     assert scalar_renderers[0].properties["y"] == "foo/bar"

tests/test_studio.py

@@ -48,11 +48,7 @@ def test_post_to_studio(tmp_dir, mocker, monkeypatch):
             "rev": mocker.ANY,
             "step": 0,
             "metrics": {live.metrics_file: {"data": {"step": 0, "foo": 1}}},
-            "plots": {
-                scalar_path: {
-                    "data": [{"timestamp": mocker.ANY, "step": 0, "foo": 1.0}]
-                }
-            },
+            "plots": {scalar_path: {"data": [{"step": 0, "foo": 1.0}]}},
             "client": "dvclive",
         },
         headers={
@@ -73,11 +69,7 @@ def test_post_to_studio(tmp_dir, mocker, monkeypatch):
             "rev": mocker.ANY,
             "step": 1,
             "metrics": {live.metrics_file: {"data": {"step": 1, "foo": 2}}},
-            "plots": {
-                scalar_path: {
-                    "data": [{"timestamp": mocker.ANY, "step": 1, "foo": 2.0}]
-                }
-            },
+            "plots": {scalar_path: {"data": [{"step": 1, "foo": 2.0}]}},
             "client": "dvclive",
         },
         headers={
@@ -139,8 +131,8 @@ def test_post_to_studio_failed_data_request(tmp_dir, mocker, monkeypatch):
             "plots": {
                 scalar_path: {
                     "data": [
-                        {"timestamp": mocker.ANY, "step": 0, "foo": 1.0},
-                        {"timestamp": mocker.ANY, "step": 1, "foo": 2.0},
+                        {"step": 0, "foo": 1.0},
+                        {"step": 1, "foo": 2.0},
                     ]
                 }
             },