Add the new release_table method (#300)

Add a new release_table to automate the retrieval of release-level information such as releaseDate, support or eol fields.

src/release_table.py

@@ -0,0 +1,54 @@
+import sys
+
+from bs4 import BeautifulSoup
+from common import dates, endoflife, http, releasedata
+
+"""Fetch release-level data from an HTML table in a web page.
+
+This script works based on a definition provided in the product's frontmatter to locate the table and extract the
+necessary information. Available configuration options are:
+
+- selector: A CSS selector used to locate one or more tables in the page.
+- headers_selector: A CSS selector used to locate the table's headers (column names).
+- rows_selector: A CSS selector used to locate the table's rows.
+- mapping: A dictionary that maps release fields to the table's columns names. All identifiers are case-insensitive.
+
+Supported CSS selectors are defined by BeautifulSoup and documented on its website. For more information, see
+https://beautiful-soup-4.readthedocs.io/en/latest/index.html?highlight=selector#css-selectors.
+
+Column data types are auto-detected. The currently supported types are 'date' (parsed using the dates module) and
+string."""
+
+METHOD = "release_table"
+
+p_filter = sys.argv[1] if len(sys.argv) > 1 else None
+m_filter = sys.argv[2] if len(sys.argv) > 2 else None
+for config in endoflife.list_configs(p_filter, METHOD, m_filter):
+    with releasedata.ProductData(config.product) as product_data:
+        response = http.fetch_url(config.url)
+        soup = BeautifulSoup(response.text, features="html5lib")
+
+        for table in soup.select(config.data["selector"]):
+            headers = [th.get_text().strip().lower() for th in table.select(config.data["headers_selector"])]
+
+            index_by_target = {}
+            for target, column in config.data["mapping"].items():
+                index_by_target[target] = headers.index(str(column).lower())
+
+            min_column_count = max(index_by_target.values()) + 1
+            for row in table.select(config.data["rows_selector"]):
+                cells = row.findAll("td")
+                if len(cells) < min_column_count:
+                    continue
+
+                release_cycle = cells[index_by_target["releaseCycle"]].get_text().strip()
+                release = product_data.get_release(release_cycle)
+                for target, index in index_by_target.items():
+                    value_str = cells[index].get_text().strip()
+
+                    try:
+                        value = dates.parse_date(value_str)
+                    except ValueError:
+                        value = value_str
+
+                    release.set_field(target, value)