Also allows to omit the end line in history requests.

Carreau · Carreau · commit 1b2e40188931 · 2025-11-28T20:35:41.000+01:00
diff --git a/IPython/core/history.py b/IPython/core/history.py
@@ -1151,13 +1151,14 @@ def __del__(self) -> None:
 # To match, e.g. ~5/8-~2/3, or ~4 (without trailing slash for full session)
 # Session numbers: ~N or N/
 # Line numbers: N (just digits, no ~ and no /)
+# Range syntax: 4-6 (with end) or 4- (without end, means "onward")
 range_re = re.compile(
     r"""
 ((?P<startsess>(?:~\d+/?|\d+/)))?
 (?P<start>\d+)?
 ((?P<sep>[\-:])
  ((?P<endsess>(?:~\d+/?|\d+/)))?
- (?P<end>\d+))?
+ (?P<end>\d*))?
 $""",
     re.VERBOSE,
 )
@@ -1175,6 +1176,10 @@ def extract_hist_ranges(ranges_str: str) -> Iterable[tuple[int, int, Optional[in
     [(-8, 5, None), (-7, 1, 5), (0, 2, 3)]
     >>> list(extract_hist_ranges("~4"))
     [(-4, 1, None)]  # Full session 4 (trailing / is optional)
+    >>> list(extract_hist_ranges("4-"))
+    [(0, 4, None)]  # From line 4 onward (to end)
+    >>> list(extract_hist_ranges("~4/4-"))
+    [(-4, 4, None)]  # From line 4 onward in session 4
     """
     if ranges_str == "":
         yield (0, 1, None)  # Everything from current session
@@ -1185,23 +1190,21 @@ def extract_hist_ranges(ranges_str: str) -> Iterable[tuple[int, int, Optional[in
         if not rmatch:
             continue
         start = rmatch.group("start")
+        sep = rmatch.group("sep")
         if start:
             start = int(start)
             end = rmatch.group("end")
-            # If no end specified, get (a, a + 1)
-            end = int(end) if end else start + 1
-        else:  # start not specified
-            if not rmatch.group("startsess"):  # no startsess
+            if sep == "-":
+                end = (int(end) + 1) if end else None
+            else:
+                end = int(end) if end else start + 1
+        else:
+            if not rmatch.group("startsess"):
                 continue
             start = 1
-            end = None  # provide the entire session hist
-
-        if rmatch.group("sep") == "-":  # 1-3 == 1:4 --> [1, 2, 3]
-            assert end is not None
-            end += 1
+            end = None
         startsess = rmatch.group("startsess") or "0"
         endsess = rmatch.group("endsess") or startsess
-        # Strip trailing / from session numbers (e.g., "~4/" -> "~4", "4/" -> "4")
         startsess = startsess.rstrip("/")
         endsess = endsess.rstrip("/")
         startsess = int(startsess.replace("~", "-"))
diff --git a/IPython/core/magics/history.py b/IPython/core/magics/history.py
@@ -121,10 +121,14 @@ def history(self, parameter_s = ''):
             Line 4, current session
         ``4-6``
             Lines 4-6, current session
-        ``~2/`` or `~2`
-            All lines of session 2 before current
+        ``4-``
+            Lines 4 onward (to end), current session
         ``243/1-5``
             Lines 1-5, session 243
+        ``~2/`` or `~2`
+            All lines of session 2 before current
+        ``~4/4-``
+            Lines 4 onward (to end), session 4 before current
         ``~2/7``
             Line 7, session 2 before current
         ``~8/1-~6/5``
diff --git a/tests/test_history.py b/tests/test_history.py
@@ -225,6 +225,10 @@ def test_extract_hist_ranges_empty_str():
         ("~1/", [(-1, 1, None)], "single digit session with slash"),
         ("~2", [(-2, 1, None)], "backward compatibility without slash"),
         ("~2/", [(-2, 1, None)], "backward compatibility with slash"),
+        ("4-", [(0, 4, None)], "from line 4 onward in current session"),
+        ("~4/4-", [(-4, 4, None)], "from line 4 onward in session 4"),
+        ("2/4-", [(2, 4, None)], "from line 4 onward in session 2"),
+        ("~5/10-", [(-5, 10, None)], "from line 10 onward in session 5"),
     ],
 )
 def test_extract_hist_ranges_without_trailing_slash(instr, expected, description):
