renamed some functions and variables; added optional parameters

src/stock-symbol-scraper/main.py

@@ -7,6 +7,7 @@ from argparse import ArgumentParser
 from pathlib import Path
 from datetime import datetime
 from string import ascii_uppercase
+from math import inf
 
 from aiohttp import ClientSession
 from bs4 import BeautifulSoup
@@ -34,20 +35,17 @@ class UnexpectedMarkupError(Exception):
     pass
 
 
-def data_from_rows(trs: ResultSet) -> list[row_type]:
-    data: list[row_type] = []
-    for row in trs:
-        data.append(get_single_row_data(row))
-    return data
+def extract_row_data(*table_rows: Tag) -> list[row_type]:
+    return [get_single_tr_data(tr) for tr in table_rows]
 
 
-def get_single_row_data(table_row: Tag) -> row_type:
+def get_single_tr_data(table_row: Tag) -> row_type:
     tds = table_row.find_all('td')
     company_name = str(tds[0].a.contents[0]).strip()
     stock_symbol = str(tds[0].a.contents[1].contents[0]).strip()
     m = re.search(STOCK_SYMBOL_PATTERN, stock_symbol)
     if m is None:
-        log.error(f"{stock_symbol} did not match the stock symbol pattern")
+        log.warning(f"{stock_symbol} did not match the stock symbol pattern; saving as is")
     else:
         stock_symbol = m.group(1)
     country = get_str_from_td(tds[1])
@@ -64,14 +62,14 @@ def get_str_from_td(td: Tag) -> str:
     return str(content).strip()
 
 
-async def all_trs_from_page(url: str, session: ClientSession = None) -> ResultSet:
+async def trs_from_page(url: str, session: ClientSession = None, limit: int = None) -> ResultSet:
     if session is None:
         session = ClientSession()
     async with session.get(url) as response:
         html = await response.text()
     soup = BeautifulSoup(html, 'html.parser')
     try:
-        return soup.find('div', {'id': 'marketsindex'}).table.tbody.find_all('tr')
+        return soup.find('div', {'id': 'marketsindex'}).table.tbody.find_all('tr', limit=limit)
     except AttributeError:
         log.error("Unexpected HTML markup!")
         file_name = f'unexpected_response_at_{datetime.now().strftime("%Y-%m-%d_%H-%M")}.html'
@@ -80,27 +78,28 @@ async def all_trs_from_page(url: str, session: ClientSession = None) -> ResultSe
         raise UnexpectedMarkupError
 
 
-async def all_data_from_category(category: str, session: ClientSession = None) -> list[row_type]:
+async def get_data_from_category(category: str, session: ClientSession = None,
+                                 first_page: int = 1, last_page: int = inf) -> list[row_type]:
     log.info(f"Getting companies starting with '{category}'")
     if session is None:
         session = ClientSession()
     data: list[row_type] = []
-    page = 1
-    trs = await all_trs_from_page(f'{BASE_URL}{category}', session)
-    while len(trs) > 0:
-        log.info(f"Scraping '{category}' page {page}")
-        data.extend(data_from_rows(trs))
+    page = first_page
+    trs = await trs_from_page(f'{BASE_URL}{category}', session)
+    while page <= last_page and len(trs) > 0:
+        data.extend(extract_row_data(*trs))
+        log.info(f"Scraped '{category}' page {page}")
         page += 1
-        trs = await all_trs_from_page(f'{BASE_URL}{category}/{page}', session)
+        trs = await trs_from_page(f'{BASE_URL}{category}/{page}', session)
     return data
 
 
-async def get_all_data(asynchronous: bool = False) -> list[row_type]:
+async def get_all_data(sequential: bool = False) -> list[row_type]:
     async with ClientSession() as session:
-        if asynchronous:
-            results = await asyncio.gather(*(all_data_from_category(category, session) for category in CATEGORIES))
+        if sequential:
+            results = [await get_data_from_category(category, session) for category in CATEGORIES]
         else:
-            results = [await all_data_from_category(category, session) for category in CATEGORIES]
+            results = await asyncio.gather(*(get_data_from_category(category, session) for category in CATEGORIES))
     data = []
     for result in results:
         data.extend(result)
@@ -128,7 +127,7 @@ def main() -> None:
     if args.verbose:
         log.setLevel(logging.DEBUG)
 
-    data = asyncio.run(get_all_data(not args.sequential))
+    data = asyncio.run(get_all_data(args.sequential))
 
     if args.to_file is None:
         csv.writer(sys.stdout).writerows(data)