Add backend unit tests

- Add unit testing code in backend/tests/
- Change to snake-case for script/file/directory names
- Use os.path.join() instead of '/'
- Refactor script code into function defs and a main-guard
- Make global vars all-caps

Some fixes:
- For getting descriptions, some wiki redirects weren't properly resolved
- Linked images were sub-optimally propagated
- Generation of reduced trees assumed a wiki-id association implied a description
- Tilo.py had potential null dereferences by not always using a reduced node set
- EOL image downloading didn't properly wait for all threads to end when finishing

3 files changed, 149 insertions, 0 deletions

diff --git a/backend/tol_data/dbpedia/README.md b/backend/tol_data/dbpedia/README.md
new file mode 100644
index 0000000..a708122
--- /dev/null
+++ b/backend/tol_data/dbpedia/README.md
@@ -0,0 +1,29 @@
+This directory holds files obtained/derived from [Dbpedia](https://www.dbpedia.org).
+
+# Downloaded Files
+-   `labels_lang=en.ttl.bz2` <br>
+    Obtained via https://databus.dbpedia.org/dbpedia/collections/latest-core.
+    Downloaded from <https://databus.dbpedia.org/dbpedia/generic/labels/2022.03.01/labels_lang=en.ttl.bz2>.
+-   `page_lang=en_ids.ttl.bz2` <br>
+    Downloaded from <https://databus.dbpedia.org/dbpedia/generic/page/2022.03.01/page_lang=en_ids.ttl.bz2>
+-   `redirects_lang=en_transitive.ttl.bz2` <br>
+    Downloaded from <https://databus.dbpedia.org/dbpedia/generic/redirects/2022.03.01/redirects_lang=en_transitive.ttl.bz2>.
+-   `disambiguations_lang=en.ttl.bz2` <br>
+    Downloaded from <https://databus.dbpedia.org/dbpedia/generic/disambiguations/2022.03.01/disambiguations_lang=en.ttl.bz2>.
+-   `instance-types_lang=en_specific.ttl.bz2` <br>
+    Downloaded from <https://databus.dbpedia.org/dbpedia/mappings/instance-types/2022.03.01/instance-types_lang=en_specific.ttl.bz2>.
+-   `short-abstracts_lang=en.ttl.bz2` <br>
+    Downloaded from <https://databus.dbpedia.org/vehnem/text/short-abstracts/2021.05.01/short-abstracts_lang=en.ttl.bz2>.
+
+# Other Files
+-   `gen_desc_data.py` <br>
+    Used to generate a database representing data from the ttl files.
+-   `desc_data.db` <br>
+    Generated by `gen_desc_data.py`. <br>
+    Tables: <br>
+    -   `labels`:          `iri TEXT PRIMARY KEY, label TEXT `
+    -   `ids`:             `iri TEXT PRIMARY KEY, id INT`
+    -   `redirects`:       `iri TEXT PRIMARY KEY, target TEXT`
+    -   `disambiguations`: `iri TEXT PRIMARY KEY`
+    -   `types`:           `iri TEXT, type TEXT`
+    -   `abstracts`:       `iri TEXT PRIMARY KEY, abstract TEXT`
diff --git a/backend/tol_data/dbpedia/__init__.py b/backend/tol_data/dbpedia/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/backend/tol_data/dbpedia/__init__.py
diff --git a/backend/tol_data/dbpedia/gen_desc_data.py b/backend/tol_data/dbpedia/gen_desc_data.py
new file mode 100755
index 0000000..50418e0
--- /dev/null
+++ b/backend/tol_data/dbpedia/gen_desc_data.py
@@ -0,0 +1,120 @@
+#!/usr/bin/python3
+
+"""
+Adds DBpedia labels/types/abstracts/etc data into a database
+"""
+
+# In testing, this script took a few hours to run, and generated about 10GB
+
+import re
+import bz2, sqlite3
+
+LABELS_FILE = 'labels_lang=en.ttl.bz2' # Had about 16e6 entries
+IDS_FILE = 'page_lang=en_ids.ttl.bz2'
+REDIRECTS_FILE = 'redirects_lang=en_transitive.ttl.bz2'
+DISAMBIG_FILE = 'disambiguations_lang=en.ttl.bz2'
+TYPES_FILE = 'instance-types_lang=en_specific.ttl.bz2'
+ABSTRACTS_FILE = 'short-abstracts_lang=en.ttl.bz2'
+DB_FILE = 'desc_data.db'
+
+def genData(
+		labelsFile: str, idsFile: str, redirectsFile: str, disambigFile: str,
+		typesFile: str, abstractsFile: str, dbFile: str) -> None:
+	""" Reads the files and writes to db """
+	print('Creating database')
+	dbCon = sqlite3.connect(dbFile)
+	dbCur = dbCon.cursor()
+	#
+	print('Reading/storing label data')
+	dbCur.execute('CREATE TABLE labels (iri TEXT PRIMARY KEY, label TEXT)')
+	dbCur.execute('CREATE INDEX labels_idx ON labels(label)')
+	dbCur.execute('CREATE INDEX labels_idx_nc ON labels(label COLLATE NOCASE)')
+	labelLineRegex = re.compile(r'<([^>]+)> <[^>]+> "((?:[^"]|\\")+)"@en \.\n')
+	with bz2.open(labelsFile, mode='rt') as file:
+		for lineNum, line in enumerate(file, 1):
+			if lineNum % 1e5 == 0:
+				print(f'At line {lineNum}')
+			match = labelLineRegex.fullmatch(line)
+			if match is None:
+				raise Exception(f'ERROR: Line {lineNum} has unexpected format')
+			dbCur.execute('INSERT INTO labels VALUES (?, ?)', (match.group(1), match.group(2)))
+	#
+	print('Reading/storing wiki page ids')
+	dbCur.execute('CREATE TABLE ids (iri TEXT PRIMARY KEY, id INT)')
+	dbCur.execute('CREATE INDEX ids_idx ON ids(id)')
+	idLineRegex = re.compile(r'<([^>]+)> <[^>]+> "(\d+)".*\n')
+	with bz2.open(idsFile, mode='rt') as file:
+		for lineNum, line in enumerate(file, 1):
+			if lineNum % 1e5 == 0:
+				print(f'At line {lineNum}')
+			match = idLineRegex.fullmatch(line)
+			if match is None:
+				raise Exception(f'ERROR: Line {lineNum} has unexpected format')
+			try:
+				dbCur.execute('INSERT INTO ids VALUES (?, ?)', (match.group(1), int(match.group(2))))
+			except sqlite3.IntegrityError as e:
+				# Accounts for certain lines that have the same IRI
+				print(f'WARNING: Failed to add entry with IRI "{match.group(1)}": {e}')
+	#
+	print('Reading/storing redirection data')
+	dbCur.execute('CREATE TABLE redirects (iri TEXT PRIMARY KEY, target TEXT)')
+	redirLineRegex = re.compile(r'<([^>]+)> <[^>]+> <([^>]+)> \.\n')
+	with bz2.open(redirectsFile, mode='rt') as file:
+		for lineNum, line in enumerate(file, 1):
+			if lineNum % 1e5 == 0:
+				print(f'At line {lineNum}')
+			match = redirLineRegex.fullmatch(line)
+			if match is None:
+				raise Exception(f'ERROR: Line {lineNum} has unexpected format')
+			dbCur.execute('INSERT INTO redirects VALUES (?, ?)', (match.group(1), match.group(2)))
+	#
+	print('Reading/storing diambiguation-page data')
+	dbCur.execute('CREATE TABLE disambiguations (iri TEXT PRIMARY KEY)')
+	disambigLineRegex = redirLineRegex
+	with bz2.open(disambigFile, mode='rt') as file:
+		for lineNum, line in enumerate(file, 1):
+			if lineNum % 1e5 == 0:
+				print(f'At line {lineNum}')
+			match = disambigLineRegex.fullmatch(line)
+			if match is None:
+				raise Exception(f'ERROR: Line {lineNum} has unexpected format')
+			dbCur.execute('INSERT OR IGNORE INTO disambiguations VALUES (?)', (match.group(1),))
+	#
+	print('Reading/storing instance-type data')
+	dbCur.execute('CREATE TABLE types (iri TEXT, type TEXT)')
+	dbCur.execute('CREATE INDEX types_iri_idx ON types(iri)')
+	typeLineRegex = redirLineRegex
+	with bz2.open(typesFile, mode='rt') as file:
+		for lineNum, line in enumerate(file, 1):
+			if lineNum % 1e5 == 0:
+				print(f'At line {lineNum}')
+			match = typeLineRegex.fullmatch(line)
+			if match is None:
+				raise Exception(f'ERROR: Line {lineNum} has unexpected format')
+			dbCur.execute('INSERT INTO types VALUES (?, ?)', (match.group(1), match.group(2)))
+	#
+	print('Reading/storing abstracts')
+	dbCur.execute('CREATE TABLE abstracts (iri TEXT PRIMARY KEY, abstract TEXT)')
+	descLineRegex = labelLineRegex
+	with bz2.open(abstractsFile, mode='rt') as file:
+		for lineNum, line in enumerate(file):
+			if lineNum % 1e5 == 0:
+				print(f'At line {lineNum}')
+			if line[0] == '#':
+				continue
+			match = descLineRegex.fullmatch(line)
+			if match is None:
+				raise Exception(f'ERROR: Line {lineNum} has unexpected format')
+			dbCur.execute('INSERT INTO abstracts VALUES (?, ?)',
+				(match.group(1), match.group(2).replace(r'\"', '"')))
+	#
+	print('Closing database')
+	dbCon.commit()
+	dbCon.close()
+
+if __name__ == '__main__':
+	import argparse
+	parser = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
+	parser.parse_args()
+	#
+	genData(LABELS_FILE, IDS_FILE, REDIRECTS_FILE, DISAMBIG_FILE, TYPES_FILE, ABSTRACTS_FILE, DB_FILE)