smaheshwar-pltr commented on code in PR #3364:
URL: https://github.com/apache/iceberg-python/pull/3364#discussion_r3260048527


##########
pyiceberg/table/__init__.py:
##########
@@ -2103,116 +2189,346 @@ def plan_files(self) -> Iterable[FileScanTask]:
             return self._plan_files_server_side()
         return self._plan_files_local()
 
-    def to_arrow(self) -> pa.Table:
-        """Read an Arrow table eagerly from this DataScan.
+    def count(self) -> int:
+        from pyiceberg.io.pyarrow import ArrowScan
 
-        All rows will be loaded into memory at once.
+        # Usage: Calculates the total number of records in a Scan that haven't 
had positional deletes.
+        res = 0
+        # every task is a FileScanTask
+        tasks = self.plan_files()
 
-        Returns:
-            pa.Table: Materialized Arrow Table from the Iceberg table's 
DataScan
-        """
-        from pyiceberg.io.pyarrow import ArrowScan
+        for task in tasks:
+            # task.residual is a Boolean Expression if the filter condition is 
fully satisfied by the
+            # partition value and task.delete_files represents that positional 
delete haven't been merged yet
+            # hence those files have to read as a pyarrow table applying the 
filter and deletes
+            if task.residual == AlwaysTrue() and len(task.delete_files) == 0:
+                # Every File has a metadata stat that stores the file record 
count
+                res += task.file.record_count
+            else:
+                arrow_scan = ArrowScan(
+                    table_metadata=self.table_metadata,
+                    io=self.io,
+                    projected_schema=self.projection(),
+                    row_filter=self.row_filter,
+                    case_sensitive=self.case_sensitive,
+                )
+                tbl = arrow_scan.to_table([task])
+                res += len(tbl)
+        return res
 
-        return ArrowScan(
-            self.table_metadata, self.io, self.projection(), self.row_filter, 
self.case_sensitive, self.limit
-        ).to_table(self.plan_files())
 
-    def to_arrow_batch_reader(self) -> pa.RecordBatchReader:
-        """Return an Arrow RecordBatchReader from this DataScan.
+IAS = TypeVar("IAS", bound="IncrementalAppendScan", covariant=True)
 
-        For large results, using a RecordBatchReader requires less memory than
-        loading an Arrow Table for the same DataScan, because a RecordBatch
-        is read one at a time.
 
-        Returns:
-            pa.RecordBatchReader: Arrow RecordBatchReader from the Iceberg 
table's DataScan
-                which can be used to read a stream of record batches one by 
one.
-        """
-        import pyarrow as pa
+class IncrementalAppendScan(BaseScan):
+    """An incremental scan of a table's data that accumulates appended data 
between two snapshots.
 
-        from pyiceberg.io.pyarrow import ArrowScan, schema_to_pyarrow
+    Args:
+        row_filter:
+            A string or BooleanExpression that describes the
+            desired rows
+        selected_fields:
+            A tuple of strings representing the column names
+            to return in the output dataframe.
+        case_sensitive:
+            If True column matching is case sensitive
+        options:
+            Additional Table properties as a dictionary of
+            string key value pairs to use for this scan.
+        limit:
+            An integer representing the number of rows to
+            return in the scan result. If None, fetches all
+            matching rows.
+        from_snapshot_id_exclusive:
+            Optional ID of the "from" snapshot, to start the incremental scan 
from, exclusively. When the scan is
+            ultimately planned, this must not be None. The snapshot does not 
need to be present in the table metadata
+            (it may have been expired), as long as it is the parent of some 
ancestor of the "to" snapshot.
+        to_snapshot_id_inclusive:
+            Optional ID of the "to" snapshot, to end the incremental scan at, 
inclusively.
+            Omitting it will default to the table's current snapshot.
+    """
 
-        target_schema = schema_to_pyarrow(self.projection())
-        batches = ArrowScan(
-            self.table_metadata, self.io, self.projection(), self.row_filter, 
self.case_sensitive, self.limit
-        ).to_record_batches(self.plan_files())
+    from_snapshot_id_exclusive: int | None
+    to_snapshot_id_inclusive: int | None
 
-        return pa.RecordBatchReader.from_batches(
-            target_schema,
-            batches,
-        ).cast(target_schema)
+    def __init__(
+        self,
+        table_metadata: TableMetadata,
+        io: FileIO,
+        row_filter: str | BooleanExpression = ALWAYS_TRUE,
+        selected_fields: tuple[str, ...] = ("*",),
+        case_sensitive: bool = True,
+        options: Properties = EMPTY_DICT,
+        limit: int | None = None,
+        from_snapshot_id_exclusive: int | None = None,
+        to_snapshot_id_inclusive: int | None = None,
+    ):
+        super().__init__(
+            table_metadata=table_metadata,
+            io=io,
+            row_filter=row_filter,
+            selected_fields=selected_fields,
+            case_sensitive=case_sensitive,
+            options=options,
+            limit=limit,
+        )
+        self.from_snapshot_id_exclusive = from_snapshot_id_exclusive
+        self.to_snapshot_id_inclusive = to_snapshot_id_inclusive
 
-    def to_pandas(self, **kwargs: Any) -> pd.DataFrame:
-        """Read a Pandas DataFrame eagerly from this Iceberg table.
+    def from_snapshot_exclusive(self: IAS, from_snapshot_id_exclusive: int | 
None) -> IAS:

Review Comment:
   Maps to Java's 
[`fromSnapshotExclusive(long)`](https://github.com/apache/iceberg/blob/2f6606a247e2b16be46ca6c02fc4cfc2e17691e6/api/src/main/java/org/apache/iceberg/IncrementalScan.java#L61).
 We don't expose the `String ref` overload or `useBranch` — Spark passes raw 
IDs anyway, and ref support can be added later without breaking anything.



##########
pyiceberg/table/__init__.py:
##########
@@ -2103,116 +2189,346 @@ def plan_files(self) -> Iterable[FileScanTask]:
             return self._plan_files_server_side()
         return self._plan_files_local()
 
-    def to_arrow(self) -> pa.Table:
-        """Read an Arrow table eagerly from this DataScan.
+    def count(self) -> int:
+        from pyiceberg.io.pyarrow import ArrowScan
 
-        All rows will be loaded into memory at once.
+        # Usage: Calculates the total number of records in a Scan that haven't 
had positional deletes.
+        res = 0
+        # every task is a FileScanTask
+        tasks = self.plan_files()
 
-        Returns:
-            pa.Table: Materialized Arrow Table from the Iceberg table's 
DataScan
-        """
-        from pyiceberg.io.pyarrow import ArrowScan
+        for task in tasks:
+            # task.residual is a Boolean Expression if the filter condition is 
fully satisfied by the
+            # partition value and task.delete_files represents that positional 
delete haven't been merged yet
+            # hence those files have to read as a pyarrow table applying the 
filter and deletes
+            if task.residual == AlwaysTrue() and len(task.delete_files) == 0:
+                # Every File has a metadata stat that stores the file record 
count
+                res += task.file.record_count
+            else:
+                arrow_scan = ArrowScan(
+                    table_metadata=self.table_metadata,
+                    io=self.io,
+                    projected_schema=self.projection(),
+                    row_filter=self.row_filter,
+                    case_sensitive=self.case_sensitive,
+                )
+                tbl = arrow_scan.to_table([task])
+                res += len(tbl)
+        return res
 
-        return ArrowScan(
-            self.table_metadata, self.io, self.projection(), self.row_filter, 
self.case_sensitive, self.limit
-        ).to_table(self.plan_files())
 
-    def to_arrow_batch_reader(self) -> pa.RecordBatchReader:
-        """Return an Arrow RecordBatchReader from this DataScan.
+IAS = TypeVar("IAS", bound="IncrementalAppendScan", covariant=True)
 
-        For large results, using a RecordBatchReader requires less memory than
-        loading an Arrow Table for the same DataScan, because a RecordBatch
-        is read one at a time.
 
-        Returns:
-            pa.RecordBatchReader: Arrow RecordBatchReader from the Iceberg 
table's DataScan
-                which can be used to read a stream of record batches one by 
one.
-        """
-        import pyarrow as pa
+class IncrementalAppendScan(BaseScan):
+    """An incremental scan of a table's data that accumulates appended data 
between two snapshots.
 
-        from pyiceberg.io.pyarrow import ArrowScan, schema_to_pyarrow
+    Args:
+        row_filter:
+            A string or BooleanExpression that describes the
+            desired rows
+        selected_fields:
+            A tuple of strings representing the column names
+            to return in the output dataframe.
+        case_sensitive:
+            If True column matching is case sensitive
+        options:
+            Additional Table properties as a dictionary of
+            string key value pairs to use for this scan.
+        limit:
+            An integer representing the number of rows to
+            return in the scan result. If None, fetches all
+            matching rows.
+        from_snapshot_id_exclusive:
+            Optional ID of the "from" snapshot, to start the incremental scan 
from, exclusively. When the scan is
+            ultimately planned, this must not be None. The snapshot does not 
need to be present in the table metadata
+            (it may have been expired), as long as it is the parent of some 
ancestor of the "to" snapshot.
+        to_snapshot_id_inclusive:
+            Optional ID of the "to" snapshot, to end the incremental scan at, 
inclusively.
+            Omitting it will default to the table's current snapshot.
+    """
 
-        target_schema = schema_to_pyarrow(self.projection())
-        batches = ArrowScan(
-            self.table_metadata, self.io, self.projection(), self.row_filter, 
self.case_sensitive, self.limit
-        ).to_record_batches(self.plan_files())
+    from_snapshot_id_exclusive: int | None
+    to_snapshot_id_inclusive: int | None
 
-        return pa.RecordBatchReader.from_batches(
-            target_schema,
-            batches,
-        ).cast(target_schema)
+    def __init__(
+        self,
+        table_metadata: TableMetadata,
+        io: FileIO,
+        row_filter: str | BooleanExpression = ALWAYS_TRUE,
+        selected_fields: tuple[str, ...] = ("*",),
+        case_sensitive: bool = True,
+        options: Properties = EMPTY_DICT,
+        limit: int | None = None,
+        from_snapshot_id_exclusive: int | None = None,
+        to_snapshot_id_inclusive: int | None = None,
+    ):
+        super().__init__(
+            table_metadata=table_metadata,
+            io=io,
+            row_filter=row_filter,
+            selected_fields=selected_fields,
+            case_sensitive=case_sensitive,
+            options=options,
+            limit=limit,
+        )
+        self.from_snapshot_id_exclusive = from_snapshot_id_exclusive
+        self.to_snapshot_id_inclusive = to_snapshot_id_inclusive
 
-    def to_pandas(self, **kwargs: Any) -> pd.DataFrame:
-        """Read a Pandas DataFrame eagerly from this Iceberg table.
+    def from_snapshot_exclusive(self: IAS, from_snapshot_id_exclusive: int | 
None) -> IAS:
+        """Instructs this scan to look for changes starting from a particular 
snapshot (exclusive).
+
+        Args:
+            from_snapshot_id_exclusive: the start snapshot ID (exclusive)
 
         Returns:
-            pd.DataFrame: Materialized Pandas Dataframe from the Iceberg table
+            this for method chaining
         """
-        return self.to_arrow().to_pandas(**kwargs)
+        return 
self.update(from_snapshot_id_exclusive=from_snapshot_id_exclusive)
 
-    def to_duckdb(self, table_name: str, connection: DuckDBPyConnection | None 
= None) -> DuckDBPyConnection:
-        """Shorthand for loading the Iceberg Table in DuckDB.
+    def to_snapshot_inclusive(self: IAS, to_snapshot_id_inclusive: int | None) 
-> IAS:
+        """Instructs this scan to look for changes up to a particular snapshot 
(inclusive).
+
+        Args:
+            to_snapshot_id_inclusive: the end snapshot ID (inclusive)
 
         Returns:
-            DuckDBPyConnection: In memory DuckDB connection with the Iceberg 
table.
+            this for method chaining
         """
-        import duckdb
+        return self.update(to_snapshot_id_inclusive=to_snapshot_id_inclusive)
 
-        con = connection or duckdb.connect(database=":memory:")
-        con.register(table_name, self.to_arrow())
+    def projection(self) -> Schema:

Review Comment:
   Always uses the table's **current** schema, unlike `TableScan.projection()` 
which uses the snapshot's schema when `snapshot_id` is set. Matches Java's 
[`BaseTable.newIncrementalAppendScan`](https://github.com/apache/iceberg/blob/2f6606a247e2b16be46ca6c02fc4cfc2e17691e6/core/src/main/java/org/apache/iceberg/BaseTable.java#L89-L92),
 which constructs the scan with `schema()` (current, not snapshot-bound), and 
C++'s 
[`TableScanBuilder::ResolveSnapshotSchema`](https://github.com/apache/iceberg-cpp/blob/fc80e4bdbafcd659e4b44fb9fb8ae7960a08c2d1/src/iceberg/table_scan.cc#L513-L526),
 which falls through to `metadata_->Schema()` for incremental scans (no 
`snapshot_id` on the context). Older-schema rows in range get NULL for new 
columns — covered by 
`test_incremental_append_scan_schema_evolution_within_range`.



##########
pyiceberg/table/__init__.py:
##########
@@ -2103,116 +2189,346 @@ def plan_files(self) -> Iterable[FileScanTask]:
             return self._plan_files_server_side()
         return self._plan_files_local()
 
-    def to_arrow(self) -> pa.Table:
-        """Read an Arrow table eagerly from this DataScan.
+    def count(self) -> int:
+        from pyiceberg.io.pyarrow import ArrowScan
 
-        All rows will be loaded into memory at once.
+        # Usage: Calculates the total number of records in a Scan that haven't 
had positional deletes.
+        res = 0
+        # every task is a FileScanTask
+        tasks = self.plan_files()
 
-        Returns:
-            pa.Table: Materialized Arrow Table from the Iceberg table's 
DataScan
-        """
-        from pyiceberg.io.pyarrow import ArrowScan
+        for task in tasks:
+            # task.residual is a Boolean Expression if the filter condition is 
fully satisfied by the
+            # partition value and task.delete_files represents that positional 
delete haven't been merged yet
+            # hence those files have to read as a pyarrow table applying the 
filter and deletes
+            if task.residual == AlwaysTrue() and len(task.delete_files) == 0:
+                # Every File has a metadata stat that stores the file record 
count
+                res += task.file.record_count
+            else:
+                arrow_scan = ArrowScan(
+                    table_metadata=self.table_metadata,
+                    io=self.io,
+                    projected_schema=self.projection(),
+                    row_filter=self.row_filter,
+                    case_sensitive=self.case_sensitive,
+                )
+                tbl = arrow_scan.to_table([task])
+                res += len(tbl)
+        return res
 
-        return ArrowScan(
-            self.table_metadata, self.io, self.projection(), self.row_filter, 
self.case_sensitive, self.limit
-        ).to_table(self.plan_files())
 
-    def to_arrow_batch_reader(self) -> pa.RecordBatchReader:
-        """Return an Arrow RecordBatchReader from this DataScan.
+IAS = TypeVar("IAS", bound="IncrementalAppendScan", covariant=True)
 
-        For large results, using a RecordBatchReader requires less memory than
-        loading an Arrow Table for the same DataScan, because a RecordBatch
-        is read one at a time.
 
-        Returns:
-            pa.RecordBatchReader: Arrow RecordBatchReader from the Iceberg 
table's DataScan
-                which can be used to read a stream of record batches one by 
one.
-        """
-        import pyarrow as pa
+class IncrementalAppendScan(BaseScan):
+    """An incremental scan of a table's data that accumulates appended data 
between two snapshots.
 
-        from pyiceberg.io.pyarrow import ArrowScan, schema_to_pyarrow
+    Args:
+        row_filter:
+            A string or BooleanExpression that describes the
+            desired rows
+        selected_fields:
+            A tuple of strings representing the column names
+            to return in the output dataframe.
+        case_sensitive:
+            If True column matching is case sensitive
+        options:
+            Additional Table properties as a dictionary of
+            string key value pairs to use for this scan.
+        limit:
+            An integer representing the number of rows to
+            return in the scan result. If None, fetches all
+            matching rows.
+        from_snapshot_id_exclusive:
+            Optional ID of the "from" snapshot, to start the incremental scan 
from, exclusively. When the scan is
+            ultimately planned, this must not be None. The snapshot does not 
need to be present in the table metadata
+            (it may have been expired), as long as it is the parent of some 
ancestor of the "to" snapshot.
+        to_snapshot_id_inclusive:
+            Optional ID of the "to" snapshot, to end the incremental scan at, 
inclusively.
+            Omitting it will default to the table's current snapshot.
+    """
 
-        target_schema = schema_to_pyarrow(self.projection())
-        batches = ArrowScan(
-            self.table_metadata, self.io, self.projection(), self.row_filter, 
self.case_sensitive, self.limit
-        ).to_record_batches(self.plan_files())
+    from_snapshot_id_exclusive: int | None
+    to_snapshot_id_inclusive: int | None
 
-        return pa.RecordBatchReader.from_batches(
-            target_schema,
-            batches,
-        ).cast(target_schema)
+    def __init__(
+        self,
+        table_metadata: TableMetadata,
+        io: FileIO,
+        row_filter: str | BooleanExpression = ALWAYS_TRUE,
+        selected_fields: tuple[str, ...] = ("*",),
+        case_sensitive: bool = True,
+        options: Properties = EMPTY_DICT,
+        limit: int | None = None,
+        from_snapshot_id_exclusive: int | None = None,
+        to_snapshot_id_inclusive: int | None = None,
+    ):
+        super().__init__(
+            table_metadata=table_metadata,
+            io=io,
+            row_filter=row_filter,
+            selected_fields=selected_fields,
+            case_sensitive=case_sensitive,
+            options=options,
+            limit=limit,
+        )
+        self.from_snapshot_id_exclusive = from_snapshot_id_exclusive
+        self.to_snapshot_id_inclusive = to_snapshot_id_inclusive
 
-    def to_pandas(self, **kwargs: Any) -> pd.DataFrame:
-        """Read a Pandas DataFrame eagerly from this Iceberg table.
+    def from_snapshot_exclusive(self: IAS, from_snapshot_id_exclusive: int | 
None) -> IAS:
+        """Instructs this scan to look for changes starting from a particular 
snapshot (exclusive).
+
+        Args:
+            from_snapshot_id_exclusive: the start snapshot ID (exclusive)
 
         Returns:
-            pd.DataFrame: Materialized Pandas Dataframe from the Iceberg table
+            this for method chaining
         """
-        return self.to_arrow().to_pandas(**kwargs)
+        return 
self.update(from_snapshot_id_exclusive=from_snapshot_id_exclusive)
 
-    def to_duckdb(self, table_name: str, connection: DuckDBPyConnection | None 
= None) -> DuckDBPyConnection:
-        """Shorthand for loading the Iceberg Table in DuckDB.
+    def to_snapshot_inclusive(self: IAS, to_snapshot_id_inclusive: int | None) 
-> IAS:
+        """Instructs this scan to look for changes up to a particular snapshot 
(inclusive).
+
+        Args:
+            to_snapshot_id_inclusive: the end snapshot ID (inclusive)
 
         Returns:
-            DuckDBPyConnection: In memory DuckDB connection with the Iceberg 
table.
+            this for method chaining
         """
-        import duckdb
+        return self.update(to_snapshot_id_inclusive=to_snapshot_id_inclusive)
 
-        con = connection or duckdb.connect(database=":memory:")
-        con.register(table_name, self.to_arrow())
+    def projection(self) -> Schema:
+        current_schema = self.table_metadata.schema()
+        if "*" in self.selected_fields:
+            return current_schema
+        return current_schema.select(*self.selected_fields, 
case_sensitive=self.case_sensitive)
 
-        return con
+    def plan_files(self) -> Iterable[FileScanTask]:

Review Comment:
   Mirrors Java's 
[`BaseIncrementalAppendScan.doPlanFiles`](https://github.com/apache/iceberg/blob/2f6606a247e2b16be46ca6c02fc4cfc2e17691e6/core/src/main/java/org/apache/iceberg/BaseIncrementalAppendScan.java#L46-L57)
 and 
[`appendFilesFromSnapshots`](https://github.com/apache/iceberg/blob/2f6606a247e2b16be46ca6c02fc4cfc2e17691e6/core/src/main/java/org/apache/iceberg/BaseIncrementalAppendScan.java#L68-L99)
 — walk ancestors, filter to `append` snapshots, dedup manifests whose 
`added_snapshot_id` is in range, then filter manifest entries by `(snapshot_id 
in range, status == ADDED)`. Set semantics on the manifest dedup match the Java 
[snippet](https://github.com/apache/iceberg/blob/2f6606a247e2b16be46ca6c02fc4cfc2e17691e6/core/src/main/java/org/apache/iceberg/BaseIncrementalAppendScan.java#L70-L74)
 and rely on `ManifestFile.__eq__`/`__hash__` being defined (which they are on 
`main` since #2233).



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