create an empty iranges object

BiocPy · Nov 29, 2023 · 80301d4 · 80301d4
1 parent 14ff5c9
commit 80301d4
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diff --git a/src/iranges/IRanges.py b/src/iranges/IRanges.py
@@ -2132,6 +2132,15 @@ def from_pandas(cls, input: "pandas.DataFrame") -> "IRanges":
 
         return cls(start=start, width=width, names=names, mcols=mcols)
 
+    @classmethod
+    def empty(cls):
+        """Create an zero-length ``IRanges`` object.
+
+        Returns:
+            same type as caller, in this case a ``IRanges``.
+        """
+        return cls([], [])
+
 
 @combine_sequences.register
 def _combine_IRanges(*x: IRanges) -> IRanges:

diff --git a/tests/test_IRanges.py b/tests/test_IRanges.py
@@ -190,3 +190,10 @@ def test_IRanges_combine():
     y = IRanges(starts2, widths2, names=["A", "B", "C", "D"])
     comb = combine_sequences(x, y)
     assert comb.get_names() == ["", "", "", "", "A", "B", "C", "D"]
+
+
+def test_empty():
+    r = IRanges.empty()
+
+    assert r is not None
+    assert isinstance(r, IRanges)