exp show: Add alternating row colors and update border style.

Use `box.HORIZONTALS`.

rich_table: Support `box.HORIZONTALS`

Closes #7128

dvc/command/experiments/show.py

@@ -373,7 +373,7 @@ def prepare_exp_id(kwargs) -> "RichText":
 
 
 def baseline_styler(typ):
-    return {"style": "bold"} if typ == "baseline" else {}
+    return {"style": "bold"} if typ == "baseline" else {"style": "default"}
 
 
 def show_experiments(
@@ -437,6 +437,9 @@ def show_experiments(
             td.drop(col)
 
     row_styles = lmap(baseline_styler, td.column("typ"))
+    for n, row_style in enumerate(row_styles):
+        if n % 2 != 0:
+            row_style["style"] += " on grey23"
 
     if not csv:
         merge_headers = ["Experiment", "rev", "typ", "parent"]
@@ -471,7 +474,7 @@ def show_experiments(
 
     td.render(
         pager=pager,
-        borders=True,
+        borders="horizontals",
         rich_table=True,
         header_styles=styles,
         row_styles=row_styles,

dvc/ui/table.py

@@ -91,6 +91,7 @@ def rich_table(
         False: None,
         "simple": box.SIMPLE,
         "minimal": box.MINIMAL,
+        "horizontals": box.HORIZONTALS,
     }
 
     table = Table(box=border_style[borders])

tests/func/experiments/test_show.py

@@ -293,7 +293,6 @@ def test_show_filter(
     from dvc.ui import ui
 
     capsys.readouterr()
-    div = "│" if os.name == "nt" else "┃"
 
     tmp_dir.gen("copy.py", COPY_SCRIPT)
     params_file = tmp_dir / "params.yaml"
@@ -340,11 +339,11 @@ def test_show_filter(
     cap = capsys.readouterr()
 
     for i in included:
-        assert f"{div} params.yaml:{i} {div}" in cap.out
-        assert f"{div} metrics.yaml:{i} {div}" in cap.out
+        assert f"params.yaml:{i}" in cap.out
+        assert f"metrics.yaml:{i}" in cap.out
     for e in excluded:
-        assert f"{div} params.yaml:{e} {div}" not in cap.out
-        assert f"{div} metrics.yaml:{e} {div}" not in cap.out
+        assert f"params.yaml:{e}" not in cap.out
+        assert f"metrics.yaml:{e}" not in cap.out
 
 
 def test_show_multiple_commits(tmp_dir, scm, dvc, exp_stage):