Add Python reprs (implemented in python)

icechunk-python/python/icechunk/display.py

@@ -0,0 +1,73 @@
+def dataclass_repr(
+    obj: object,
+    # make this default to inspecting the cls?
+    cls_name: str,
+    attributes: list[str] = None,
+    # TODO optional indent
+) -> str:
+    """
+    Dynamically create a repr for this dataclass-like object.
+
+    Parameters
+    ----------
+    obj : object
+        Object for which to make a repr.
+    cls_name : Type
+        What to display as the name of the class, including submodule.
+    attributes : list[str] | None
+        Names of attributes or properties to display the values of. 
+        These must all exist on the instance and be printable.
+
+    Returns
+    -------
+    str
+        Repr for the class.
+    """
+    header = f"<{cls_name}>"
+
+    if not attributes:
+        return header
+    else:
+        contents = []
+        for attr_name in attributes:
+            line = f"{attr_name}: {getattr(obj, attr_name)}"
+            contents.append(line)
+        return "\n".join([header] + contents)
+
+
+
+def dataclass_html_repr(
+    obj: object,
+    # make this default to inspecting the cls?
+    cls_name: str,
+    attributes: list[str] | None = None,
+    # TODO optional indent
+) -> str:
+    """
+    Dynamically create a repr for this dataclass-like object.
+
+    Parameters
+    ----------
+    obj : object
+        Object for which to make a repr.
+    cls_name : Type
+        What to display as the name of the class, including submodule.
+    attributes : list[str] | None
+        Names of attributes or properties to display the values of. 
+        These must all exist on the instance and be printable.
+
+    Returns
+    -------
+    str
+        Repr for the class.
+    """
+    header = f"<{cls_name}>"
+
+    if not attributes:
+        return header
+    else:
+        contents = []
+        for attr_name in attributes:
+            line = f"{attr_name}: {getattr(obj, attr_name)}"
+            contents.append(line)
+        return "\n".join([header] + contents)

icechunk-python/python/icechunk/session.py

@@ -10,6 +10,7 @@
 )
 from icechunk._icechunk_python import PySession
 from icechunk.store import IcechunkStore
+import icechunk.display as display
 
 
 class Session:
@@ -22,6 +23,21 @@ def __init__(self, session: PySession):
         self._session = session
         self._allow_changes = False
 
+    def __repr__(self) -> str:
+        mutable_attributes=[
+            "read_only",
+            "snapshot_id",
+        ]
+
+        if not self.read_only:
+            mutable_attributes += ["branch", "has_uncommitted_changes"]
+
+        return display.dataclass_repr(
+            obj=self,
+            cls_name="icechunk.Session",
+            attributes=mutable_attributes,
+        )
+
     def __eq__(self, value: object) -> bool:
         if not isinstance(value, Session):
             return False