Add a small utility for extracting PostgreSQL SQL and pl/pgsql keywords from the interwebs.

tools/requirements.txt

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+requests>=2.21.0
+requests[security]>=2.21.0

tools/sql_keywords.py

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+# -*- coding: utf-8 -*-
+
+##########################################################################
+#
+# pgAdmin 4 - PostgreSQL Tools
+#
+# Copyright (C) 2013 - 2019, The pgAdmin Development Team
+# This software is released under the PostgreSQL Licence
+#
+##########################################################################
+
+# This utility will extract SQL keywords from postgres website and
+# pgsql keywords from the code git paths mentioned in PG_CODES_URLS
+# Note that, PG_CODES_URLS may need to be changed manually per version change
+
+from __future__ import print_function
+import re
+import requests
+import argparse
+
+PG_CODES_URLS = [
+    "https://git.postgresql.org/gitweb/?p=postgresql.git;a=blob_plain;"
+    "f=src/pl/plpgsql/src/pl_scanner.c",
+]
+PG_CODES_REGEX = "PG_KEYWORD\(\"([a-z]*)\"[A-Z_, ]*\)"
+
+PG_SQL_DOCS_URL = \
+    "https://www.postgresql.org/docs/current/sql-keywords-appendix.html"
+PG_SQL_DOCS_REGEX = "<[a-z =\"]*>([A-Z_]*)"
+
+PG_CURRENT_VERSION_URL = "https://www.postgresql.org/docs/current/index.html"
+PG_CURRENT_VERSION_REGEX = "PostgreSQL ([0-9.]+) Documentation"
+
+
+def apply_regex(text, regex):
+    return re.findall(regex, text)
+
+
+def get_file_from_url(url):
+    req = requests.get(url)
+    return req.text
+
+
+def extract_keywords(text, regex):
+    keywords = apply_regex(text, regex)
+    return [k.lower() for k in keywords]
+
+
+def get_release_tag(current_url=PG_CURRENT_VERSION_URL,
+                    version_regex=PG_CURRENT_VERSION_REGEX):
+    resp_text = get_file_from_url(current_url)
+    version = apply_regex(resp_text, version_regex)
+    if type(version) == list:
+        version = version[0]
+
+    return "REL_" + version.replace(".", "_")
+
+
+def get_keywords_pg_code(file_urls=PG_CODES_URLS,
+                         keyword_regex=PG_CODES_REGEX):
+    keywords = []
+
+    # Lets get the latest version first
+    rel_tag = get_release_tag()
+    for file_url in file_urls:
+        if "hb" not in file_url:
+            file_url = file_url + ";hb=" + rel_tag
+        resp_text = get_file_from_url(file_url)
+
+        # Sample entry - PG_KEYWORD("begin", K_BEGIN, RESERVED_KEYWORD)
+        keywords.extend(extract_keywords(resp_text, keyword_regex))
+
+    return keywords
+
+
+def get_keywords_pg_docs(docs_url=PG_SQL_DOCS_URL,
+                         keyword_regex=PG_SQL_DOCS_REGEX):
+    resp_text = get_file_from_url(docs_url)
+    # Sample entry - <code class="token">ABORT</code>
+    keywords = extract_keywords(resp_text, keyword_regex)
+
+    return keywords
+
+
+def get_all_keywords():
+    final_keywords = set()
+
+    final_keywords.update(get_keywords_pg_code())
+    final_keywords.update(get_keywords_pg_docs())
+
+    return len(final_keywords), " ".join(sorted(list(final_keywords))).strip()
+
+
+if __name__ == '__main__':
+    args_parser = argparse.ArgumentParser(description="SQL Keywords extractor")
+    args_parser.add_argument(
+        '--total',
+        help="Print with total number of keywords",
+        action="store_true"
+    )
+    args = args_parser.parse_args()
+
+    total, keywords = get_all_keywords()
+    if args.total:
+        print(keywords + "%s\n\n%d keywords extracted." % (keywords, total))
+    else:
+        print(keywords)