support partitioning output parquet by namespace.

src/wikiq/__init__.py

@@ -5,23 +5,21 @@
 # additions_size deletions_size
 
 import argparse
-import sys
 import os.path
 import re
-from io import TextIOWrapper
-from itertools import groupby
-
-from subprocess import Popen, PIPE
+import sys
 from collections import deque
 from hashlib import sha1
-from typing import Any, IO, TextIO, Generator, Union
+from io import TextIOWrapper
+from itertools import groupby
+from subprocess import PIPE, Popen
+from typing import IO, Any, Generator, TextIO, Union
 
-import mwxml
-from mwxml import Dump
-
-from deltas.tokenizers import wikitext_split
 import mwpersistence
 import mwreverts
+import mwxml
+from deltas.tokenizers import wikitext_split
+from mwxml import Dump
 
 import wikiq.tables as tables
 from wikiq.tables import RevisionTable
@@ -29,11 +27,13 @@ from wikiq.wiki_diff_matcher import WikiDiffMatcher
 
 TO_ENCODE = ('title', 'editor')
 PERSISTENCE_RADIUS = 7
-from deltas import SequenceMatcher, SegmentMatcher
+from pathlib import Path
 
 import pyarrow as pa
-import pyarrow.parquet as pq
 import pyarrow.csv as pacsv
+import pyarrow.parquet as pq
+from deltas import SegmentMatcher, SequenceMatcher
+
 
 class PersistMethod:
     none = 0
@@ -215,7 +215,8 @@ class WikiqParser:
                  namespaces: Union[list[int], None] = None,
                  revert_radius: int = 15,
                  output_parquet: bool = True,
-                 parquet_buffer_size: int = 2000
+                 parquet_buffer_size: int = 2000,
+                 partition_namespaces: bool = False,
                  ):
 
         """ 
@@ -230,6 +231,7 @@ class WikiqParser:
         self.revert_radius = revert_radius
         self.diff = diff
         self.text = text
+        self.partition_namespaces = partition_namespaces
         if namespaces is not None:
             self.namespace_filter = set(namespaces)
         else:
@@ -374,7 +376,25 @@ class WikiqParser:
         if self.output_parquet:
             pageid_sortingcol = pq.SortingColumn(schema.get_field_index('pageid'))
             revid_sortingcol = pq.SortingColumn(schema.get_field_index('pageid'))
-            writer = pq.ParquetWriter(self.output_file, schema, flavor='spark', sorting_columns=[pageid_sortingcol, revid_sortingcol])
+            sorting_cols = [pageid_sortingcol, revid_sortingcol]
+                            
+            if self.partition_namespaces is False:
+                writer = pq.ParquetWriter(self.output_file, schema, flavor='spark', sorting_columns=sorting_cols)
+            else:
+                output_path = Path(self.output_file)
+                if self.namespace_filter is not None:
+                    namespaces = self.namespace_filter
+                else:
+                    namespaces = self.namespaces.values()
+                ns_paths = {ns: (output_path.parent / f"namespace={ns}") / output_path.name for ns in namespaces}
+                for path in ns_paths.values():
+                    Path(path).parent.mkdir(exist_ok=True, parents=True)
+                pq_writers = {ns:
+                              pq.ParquetWriter(path,
+                                               schema,
+                                               flavor='spark',
+                                               sorting_columns=sorting_cols) for ns, path in ns_paths.items()}
+
         else:
             writer = pacsv.CSVWriter(self.output_file, schema, write_options=pacsv.WriteOptions(delimiter='\t'))
 
@@ -507,6 +527,9 @@ class WikiqParser:
                 if not self.text:
                     del row_buffer['text']
 
+            if self.partition_namespaces is True:
+                writer = pq_writers[page.mwpage.namespace]
+
             writer.write(pa.table(row_buffer, schema=schema))
 
             page_count += 1
@@ -609,6 +632,10 @@ def main():
                         action='store_true',
                         help="Output the text of the revision.")
 
+    parser.add_argument('-PNS', '--partition-namespaces', dest="partition_namespaces", default=False,
+                        action='store_true',
+                        help="Partition parquet files by namespace.")
+
     parser.add_argument('--fandom-2020', dest="fandom_2020",
                         action='store_true',
                         help="Whether the archive is from the fandom 2020 dumps by Wikiteam. These dumps can have multiple .xml files in their archives.")
@@ -670,6 +697,7 @@ def main():
                                 text=args.text,
                                 diff=args.diff,
                                 output_parquet=output_parquet,
+                                partition_namespaces=args.partition_namespaces
                                 )
 
             wikiq.process()

test/Wikiq_Unit_Test.py

@@ -199,6 +199,19 @@ def test_collapse_user():
     baseline = pd.read_table(tester.baseline_file)
     assert_frame_equal(test, baseline, check_like=True)
 
+def test_partition_namespaces():
+    tester = WikiqTester(SAILORMOON, "collapse-user", in_compression="7z", out_format='parquet', baseline_format='parquet')
+
+    try:
+        tester.call_wikiq("--collapse-user", "--fandom-2020", "--partition-namespaces")
+    except subprocess.CalledProcessError as exc:
+        pytest.fail(exc.stderr.decode("utf8"))
+
+    test = pd.read_parquet(os.path.join(tester.output,"namespace=10/sailormoon.parquet"))
+    baseline = pd.read_parquet(tester.baseline_file)
+    assert_frame_equal(test, baseline, check_like=True)
+
+
 def test_pwr_wikidiff2():
     tester = WikiqTester(SAILORMOON, "persistence_wikidiff2", in_compression="7z")