extensive docstrings; made all functions public (not protected); minor refactoring

.coveragerc

@@ -8,3 +8,5 @@ omit =
 fail_under = 100
 show_missing = True
 skip_covered = True
+exclude_lines =
+    if __name__ == .__main__.:

README.md

@@ -8,15 +8,23 @@ Asynchronous HTTP requests are currently used by default.
 
 - [Python](https://www.python.org/) 3.8+
 
-Should run on most Linux/Windows systems. Tested on Arch.
+Should run on most Linux/Windows systems. Tested on Arch and Windows 10.
 
 ### Building
 
-Clone this repo, install `build` via pip, then run `pip -m build` 
+Clone this repo, install `build` via pip, then run `python -m build` 
 from the repository's root directory. This should produce a `dist/` 
 subdirectory with a wheel (build) and archive (source) distribution.
 The resulting `whl`-file can be installed via `pip install path/dist/***.whl`.
 
 ### Running
 
-...
+```shell
+$ python -m mwfin -h
+```
+gives a description of available CLI parameters and their usage. For example, running
+
+```shell
+$ python -m mwfin -f output.json -Q AAPL
+```
+will retrieve the most current available quarterly data from all three financial statements Apple Inc. has published and save it in JSON format to `output.json`.

requirements/common.txt

@@ -1,2 +1,3 @@
 beautifulsoup4
 aiohttp
+webutils-df

setup.cfg

@@ -23,6 +23,7 @@ python_requires = >=3.8
 install_requires =
     beautifulsoup4
     aiohttp
+    webutils-df
 
 [options.extras_require]
 tests =

src/mwfin/__init__.py

@@ -0,0 +1 @@
+from .functions import get_balance_sheet, get_income_statement, get_cash_flow_statement, get_all_financials

src/mwfin/__main__.py

@@ -0,0 +1,95 @@
+import logging
+import asyncio
+import json
+from argparse import ArgumentParser
+from pathlib import Path
+
+from .functions import get_all_financials
+from .constants import MAIN_LOGGER_NAME, DEFAULT_CONCURRENT_BATCH_SIZE
+
+
+log = logging.getLogger(MAIN_LOGGER_NAME)
+
+TICKER_SYMBOL = 'ticker_symbol'
+QUARTERLY = 'quarterly'
+BATCH_SIZE = 'concurrent_batch_size'
+TO_FILE = 'to_file'
+JSON_INDENT = 'json_indent'
+VERBOSE = 'verbose'
+
+
+def parse_cli() -> dict:
+    """Returns the parsed command line arguments for the program as a dictionary."""
+    parser = ArgumentParser(description="Scrape company financials")
+    parser.add_argument(
+        TICKER_SYMBOL,
+        type=str,
+        nargs='+',
+        help="Stock ticker symbol of the company to be scraped the financials of"
+    )
+    parser.add_argument(
+        '-Q', f'--{QUARTERLY}',
+        action='store_true',
+        help="If set, the financial data for the last quarters is returned; otherwise yearly data is returned."
+    )
+    parser.add_argument(
+        '-b', f'--{BATCH_SIZE.replace("_", "-")}',
+        type=int,
+        default=DEFAULT_CONCURRENT_BATCH_SIZE,
+        help="If multiple ticker symbols are passed, the company financials can be scraped concurrently. "
+             "This argument determines how many companies are scraped concurrently. "
+             "By default, they are scraped sequentially (i.e. a batch size of 1)."
+    )
+    parser.add_argument(
+        '-f', f'--{TO_FILE.replace("_", "-")}',
+        type=Path,
+        help="Writes results to the specified destination file. If omitted results are printed to stdout."
+    )
+    parser.add_argument(
+        f'--{JSON_INDENT.replace("_", "-")}',
+        type=int,
+        help="If set to a positive integer and the output format is JSON (default), the resulting JSON document is "
+             "indented accordingly for more readability; if omitted, output is returned in one line."
+    )
+    parser.add_argument(
+        '-v', f'--{VERBOSE}',
+        action='count',
+        default=0,
+        help="Verbose mode. Reduces the log level and thus prints out more status messages while running. "
+             "Using this flag multiple times increases verbosity further."
+    )
+    return vars(parser.parse_args())
+
+
+def configure_logging(verbosity: int) -> None:
+    """
+    Sets up logging by adding a stdout-handler and setting the root logger's level according to the specified verbosity.
+    A verbosity of 0 (or less) sets the log level to CRITICAL.
+    """
+    root_logger = logging.getLogger()
+    root_logger.addHandler(logging.StreamHandler())
+    root_logger.setLevel(logging.CRITICAL)
+    if verbosity > 2:
+        root_logger.setLevel(logging.DEBUG)
+    elif verbosity == 2:
+        root_logger.setLevel(logging.INFO)
+    elif verbosity == 1:
+        root_logger.setLevel(logging.WARNING)
+
+
+async def main() -> None:
+    """Parses CLI arguments, configures logging to stderr, performs the scraping, and prints/saves the data."""
+    args = parse_cli()
+    configure_logging(args[VERBOSE])
+    data = await get_all_financials(*args[TICKER_SYMBOL], quarterly=args[QUARTERLY],
+                                    concurrent_batch_size=args[BATCH_SIZE])
+    path: Path = args[TO_FILE]
+    if path is None:
+        print(json.dumps(data, indent=args[JSON_INDENT]))
+        return
+    with open(path, 'w') as f:
+        json.dump(data, f, indent=args[JSON_INDENT])
+
+
+if __name__ == '__main__':
+    asyncio.run(main())

src/mwfin/constants.py

@@ -0,0 +1,19 @@
+MAIN_LOGGER_NAME = 'mwfin'
+
+HTML_PARSER = 'html.parser'
+DOMAIN = 'www.marketwatch.com'
+BASE_URL = f'https://{DOMAIN}/investing/stock'
+DEFAULT_CONCURRENT_BATCH_SIZE = 1
+
+BS, IS, CF = 'Balance Sheet', 'Income Statement', 'Cash Flow Statement'
+FIN_STMT_URL_SUFFIX = {
+    BS: '/balance-sheet',
+    IS: '',
+    CF: '/cash-flow'
+}
+INDENT_MAP = {
+    'indent--small': 1,
+    'indent--medium': 2,
+    'indent--large': 3,
+}
+END_DATE = 'End Date'

src/mwfin/functions.py

@@ -0,0 +1,285 @@
+import logging
+import asyncio
+from typing import Union, Tuple, Dict
+
+from aiohttp.client import ClientSession
+from bs4 import BeautifulSoup
+from bs4.element import Tag, ResultSet
+from webutils import in_async_session, gather_in_batches
+
+from .constants import (HTML_PARSER, BASE_URL, END_DATE, BS, IS, CF, FIN_STMT_URL_SUFFIX, DEFAULT_CONCURRENT_BATCH_SIZE,
+                        INDENT_MAP)
+
+
+log = logging.getLogger(__name__)
+
+# First element in each Tuple is an integer indicating the row indent
+HeaderData = Tuple[int, str, str, str, str, str]
+RowData = Tuple[int, float, float, float, float, float]
+# The resulting dictionary's keys correspond to the name of the item (row) in the financial statement.
+# The first value is a tuple of the end dates of the reporting periods as strings (see above).
+# The other values are the actual data tuples containing the financial figures.
+ResultDict = dict[str, Union[HeaderData, RowData]]
+
+
+@in_async_session
+async def soup_from_url(url: str, session: ClientSession = None) -> BeautifulSoup:
+    """
+    Requests a web page and turns the response text into BeautifulSoup.
+
+    Args:
+        url:
+            The GET request is sent to this URL
+        session (optional):
+            If passed an `aiohttp.ClientSession` object, it will be used to perform the request.
+            Otherwise a new session is created and automatically closed after the request (see `@in_async_session`).
+
+    Returns:
+        The parsed html response text as BeautifulSoup
+    """
+    async with session.get(url) as response:
+        html = await response.text()
+    return BeautifulSoup(html, HTML_PARSER)
+
+
+def get_row_indent(tr: Tag) -> int:
+    """
+    Determines the visual indent of a table row.
+    Some positions in a financial statement have sub-positions below them indicated by indentation of the text in the
+    position name's cell.
+
+    Args:
+        tr: The table row element
+
+    Returns:
+        Each indentation level corresponds to an integer. 0 = no indentation, 1 = small, 2 = medium, 3 = large
+    """
+    try:
+        classes = tr.div.attrs['class']
+    except KeyError:
+        return 0
+    for class_name, indent in INDENT_MAP.items():
+        if class_name in classes:
+            return indent
+    return 0
+
+
+def extract_end_dates(soup: BeautifulSoup) -> HeaderData:
+    """
+    Finds and returns the end dates of the reporting periods as strings (either years or quarters) from the page of a
+    financial statement.
+
+    Args:
+        soup: The parsed page containing the financial statement
+
+    Returns:
+        A 6-tuple, the first element being the indent (in this case 0) and the rest being the actual end dates.
+    """
+    tr = soup.find('div', attrs={'class': 'financials'}).thead.tr
+    ths = tr.find_all('th')
+    return (0, ) + tuple(str(th.string).strip() for th in ths[1:-1])
+
+
+def get_all_table_rows(soup: BeautifulSoup) -> ResultSet:
+    """
+    Returns the table rows containing the data of interest.
+
+    Args:
+        soup: The parsed page containing the financial statement
+
+    Returns:
+        All table rows containing data from the financial statement
+    """
+    return soup.find('div', attrs={'class': 'financials'}).tbody.find_all('tr')
+
+
+def extract_row_data(tr: Tag) -> Tuple[str, RowData]:
+    """
+    Returns the name of the item displayed in the table row (of a financial statement)
+    as well as the position's indent and a figure for each reporting period.
+
+    Args:
+        tr: A table row containing data from a financial statement
+
+    Returns:
+        2-tuple where the 1st element is the position's name and the second is a 6-tuple, of which the first element is
+        the indent and the rest are the actual figures.
+    """
+    item_name = str(tr.td.div.string).strip()
+    data_div = tr.find_all('td')[-1].div.div
+    values_str: str = data_div.attrs['data-chart-data']
+    values = tuple(float(s if s != '' else 0) for s in values_str.split(','))
+    return item_name, (get_row_indent(tr), ) + values
+
+
+def extract_all_data(soup: BeautifulSoup) -> ResultDict:
+    """
+    Extracts financials from the page, which can contain either a balance sheet, income statement or cash flow
+    statement.
+
+    Args:
+        soup: The parsed page containing a financial statement
+
+    Returns:
+        Custom result dictionary (see `ResultDict`)
+    """
+    output = {END_DATE: extract_end_dates(soup)}
+    for row in get_all_table_rows(soup):
+        row_data = extract_row_data(row)
+        output[row_data[0]] = row_data[1]
+    return output
+
+
+@in_async_session
+async def get_single_company_fin_stmt(statement: str, ticker_symbol: str, quarterly: bool = False,
+                                      session: ClientSession = None) -> ResultDict:
+    """
+    Returns data from the specified financial statement of the specified company.
+
+    Args:
+        statement:
+            Must be one of the strings defined in the constants `BS`, `IS`, `CF`
+        ticker_symbol:
+            The company's stock ticker symbol
+        quarterly (optional):
+            If true the financial data of the last five quarters is scraped; otherwise (default) the last five years.
+        session (optional):
+            See `soup_from_url`
+
+    Returns:
+        Custom result dictionary (see `ResultDict`)
+    """
+    log.info(f"Scraping {statement} for {ticker_symbol}")
+    url = f'{BASE_URL}/{ticker_symbol}/financials{FIN_STMT_URL_SUFFIX[statement]}'
+    if quarterly:
+        url += '/quarter'
+    soup = await soup_from_url(url, session)
+    return extract_all_data(soup)
+
+
+@in_async_session
+async def get_multi_companies_fin_stmt(statement: str, *ticker_symbols: str, quarterly: bool = False,
+                                       concurrent_batch_size: int = DEFAULT_CONCURRENT_BATCH_SIZE,
+                                       session: ClientSession = None) -> Union[ResultDict, Dict[str, ResultDict]]:
+    """
+    Returns data from the specified financial statement of the specified companies.
+
+    Args:
+        statement:
+            See `get_single_company_fin_stmt`
+        ticker_symbols:
+            Arbitrary number of companies' stock ticker symbols
+        quarterly (optional):
+            See `get_single_company_fin_stmt`
+        concurrent_batch_size (optional):
+            If multiple ticker symbols are passed, the company financials can be scraped concurrently.
+            This argument determines how many companies are scraped concurrently.
+            By default, they are scraped sequentially (i.e. a batch size of 1).
+        session (optional):
+            See `get_single_company_fin_stmt`
+
+    Returns:
+        If only one ticker symbol is passed, the `ResultDict` for that financial statement is returned. If multiple
+        symbols are passed, a dictionary is returned, where the keys are the symbols and the values are the
+        corresponding `ResultDict`s.
+    """
+    if len(ticker_symbols) == 1:
+        return await get_single_company_fin_stmt(statement, ticker_symbols[0], quarterly, session)
+    coroutines = (get_single_company_fin_stmt(statement, symbol, quarterly, session) for symbol in ticker_symbols)
+    result_list = await gather_in_batches(concurrent_batch_size, *coroutines)
+    return {symbol: data for symbol, data in zip(ticker_symbols, result_list)}
+
+
+@in_async_session
+async def get_balance_sheet(*ticker_symbols: str, quarterly: bool = False,
+                            concurrent_batch_size: int = DEFAULT_CONCURRENT_BATCH_SIZE,
+                            session: ClientSession = None) -> Union[ResultDict, Dict[str, ResultDict]]:
+    """
+    Returns data from the balance sheet of the specified companies.
+    Convenience function around `get_multi_companies_fin_stmt`
+    """
+    return await get_multi_companies_fin_stmt(BS, *ticker_symbols,
+                                              quarterly=quarterly, concurrent_batch_size=concurrent_batch_size,
+                                              session=session)
+
+
+@in_async_session
+async def get_income_statement(*ticker_symbols: str, quarterly: bool = False,
+                               concurrent_batch_size: int = DEFAULT_CONCURRENT_BATCH_SIZE,
+                               session: ClientSession = None) -> Union[ResultDict, Dict[str, ResultDict]]:
+    """
+    Returns data from the income statement of the specified companies.
+    Convenience function around `get_multi_companies_fin_stmt`
+    """
+    return await get_multi_companies_fin_stmt(IS, *ticker_symbols,
+                                              quarterly=quarterly, concurrent_batch_size=concurrent_batch_size,
+                                              session=session)
+
+
+@in_async_session
+async def get_cash_flow_statement(*ticker_symbols: str, quarterly: bool = False,
+                                  concurrent_batch_size: int = DEFAULT_CONCURRENT_BATCH_SIZE,
+                                  session: ClientSession = None) -> Union[ResultDict, Dict[str, ResultDict]]:
+    """
+    Returns data from the cash flow statement of the specified companies.
+    Convenience function around `get_multi_companies_fin_stmt`
+    """
+    return await get_multi_companies_fin_stmt(CF, *ticker_symbols,
+                                              quarterly=quarterly, concurrent_batch_size=concurrent_batch_size,
+                                              session=session)
+
+
+@in_async_session
+async def get_single_company_all_financials(ticker_symbol: str, quarterly: bool = False,
+                                            session: ClientSession = None) -> Dict[str, ResultDict]:
+    """
+    Returns data from all financial statements of the specified company.
+    Concurrently calls `get_single_company_fin_stmt` three times.
+
+    Args:
+        ticker_symbol:
+            The company's stock ticker symbol
+        quarterly (optional):
+            See `get_single_company_fin_stmt`
+        session (optional):
+            See `get_single_company_fin_stmt`
+
+    Returns:
+        A dictionary where the keys are the three different statement names and the values are the
+        corresponding `ResultDict`s
+    """
+    coroutines = (get_single_company_fin_stmt(stmt, ticker_symbol, quarterly, session) for stmt in (BS, IS, CF))
+    results = await asyncio.gather(*coroutines)
+    return {stmt: data for stmt, data in zip((BS, IS, CF), results)}
+
+
+@in_async_session
+async def get_all_financials(*ticker_symbols: str, quarterly: bool = False,
+                             concurrent_batch_size: int = DEFAULT_CONCURRENT_BATCH_SIZE,
+                             session: ClientSession = None) -> Union[Dict[str, ResultDict],
+                                                                     Dict[str, Dict[str, ResultDict]]]:
+    """
+    Returns all fundamentals (balance sheet, income statement and cash flow statement) of the specified companies.
+
+    Args:
+        ticker_symbols:
+            Arbitrary number of companies' stock ticker symbols
+        quarterly (optional):
+            See `get_single_company_all_financials`
+        concurrent_batch_size (optional):
+            If multiple ticker symbols are passed, the company financials can be scraped concurrently.
+            This argument determines how many companies are scraped concurrently.
+            By default, they are scraped sequentially (i.e. a batch size of 1).
+        session (optional):
+            See `get_single_company_all_financials`
+
+    Returns:
+        If only one ticker symbol is passed, the output of `get_single_company_all_financials` is returned. If multiple
+        symbols are passed, a dictionary is returned, where the keys are the symbols and the values are the
+        corresponding outputs of `get_single_company_all_financials`.
+    """
+    if len(ticker_symbols) == 1:
+        return await get_single_company_all_financials(ticker_symbols[0], quarterly, session)
+    coroutines = (get_single_company_all_financials(symbol, quarterly, session) for symbol in ticker_symbols)
+    result_list = await gather_in_batches(concurrent_batch_size, *coroutines)
+    return {symbol: data for symbol, data in zip(ticker_symbols, result_list)}

tests/test_functions.py

@@ -0,0 +1,243 @@
+import logging
+from pathlib import Path
+from unittest import IsolatedAsyncioTestCase
+from unittest.mock import patch, MagicMock, AsyncMock, call
+
+from bs4 import BeautifulSoup
+
+from mwfin import functions
+from mwfin.constants import HTML_PARSER, BASE_URL, FIN_STMT_URL_SUFFIX, IS, BS, CF, END_DATE
+
+
+THIS_DIR = Path(__file__).parent
+
+
+class FunctionsTestCase(IsolatedAsyncioTestCase):
+    # boiled down & accurate structure of a relevant data table
+    # https://www.marketwatch.com/investing/stock/aapl/financials/cash-flow
+    # view page source @ line 2055
+    TEST_HTML_FILE_PATH = Path(THIS_DIR, 'test_structure.html')
+
+    log_lvl: int
+    test_html: str
+
+    @staticmethod
+    def get_mock_session(response_text: str = None) -> MagicMock:
+        mock_response = MagicMock()
+        mock_response.text = AsyncMock(return_value=response_text)
+        mock_get_return = MagicMock()
+        mock_get_return.__aenter__ = AsyncMock(return_value=mock_response)
+        mock_session_obj = MagicMock()
+        mock_session_obj.get = MagicMock(return_value=mock_get_return)
+        return mock_session_obj
+
+    @classmethod
+    def setUpClass(cls) -> None:
+        with open(cls.TEST_HTML_FILE_PATH, 'r') as f:
+            cls.test_html = f.read()
+        cls.test_soup = BeautifulSoup(cls.test_html, HTML_PARSER)
+        cls.log_lvl = functions.log.level
+        functions.log.setLevel(logging.CRITICAL)
+
+    @classmethod
+    def tearDownClass(cls) -> None:
+        functions.log.setLevel(cls.log_lvl)
+
+    @patch.object(functions, 'ClientSession')
+    async def test_soup_from_url(self, mock_session_cls):
+        test_html = '<b>foo</b>'
+        mock_session_cls.return_value = mock_session_obj = self.get_mock_session(test_html)
+        expected_output = BeautifulSoup(test_html, 'html.parser')
+        output = await functions.soup_from_url('baz', mock_session_obj)
+        self.assertEqual(expected_output, output)
+
+    def test_get_row_indent(self):
+        mock_row = BeautifulSoup('<tr><div>foo</div></tr>', HTML_PARSER).tr
+        expected_output = 0
+        output = functions.get_row_indent(mock_row)
+        self.assertEqual(expected_output, output)
+        trs = self.test_soup.find_all('tr')
+        output = functions.get_row_indent(trs[0])
+        self.assertEqual(expected_output, output)
+        for i, tr in enumerate(trs[1:], start=1):
+            output = functions.get_row_indent(tr)
+            self.assertEqual(i, output)
+
+    @patch.object(functions, 'get_row_indent')
+    def test_extract_end_dates(self, mock_get_row_indent):
+        mock_get_row_indent.return_value = 0
+        expected_output = (0, 'End_Date_1', 'End_Date_2')
+        output = functions.extract_end_dates(self.test_soup)
+        self.assertTupleEqual(expected_output, output)
+        mock_get_row_indent.assert_called_once_with(self.test_soup.tr)
+
+    def test_get_all_table_rows(self):
+        expected_output = self.test_soup.find('div', attrs={'class': 'financials'}).tbody.find_all('tr')
+        output = functions.get_all_table_rows(self.test_soup)
+        self.assertSequenceEqual(expected_output, output)
+
+    @patch.object(functions, 'get_row_indent')
+    def test_extract_row_data(self, mock_get_row_indent):
+        mock_get_row_indent.return_value = 1
+        test_row = self.test_soup.find('div', attrs={'class': 'financials'}).tbody.tr
+        expected_output = ('foo', (1, 1., -2.))
+        output = functions.extract_row_data(test_row)
+        self.assertTupleEqual(expected_output, output)
+        mock_get_row_indent.assert_called_once_with(test_row)
+
+    @patch.object(functions, 'extract_row_data')
+    @patch.object(functions, 'get_all_table_rows')
+    @patch.object(functions, 'extract_end_dates')
+    def test_extract_all_data(self, mock_extract_end_dates, mock_get_all_table_rows, mock_extract_row_data):
+        test_end_dates = ('foo', 'bar')
+        mock_extract_end_dates.return_value = test_end_dates
+        test_relevant_rows = ['tr1', 'tr2']
+        mock_get_all_table_rows.return_value = test_relevant_rows
+        test_row_data = ('item_name', (123, 456))
+        mock_extract_row_data.return_value = test_row_data
+        expected_output = {
+            END_DATE: test_end_dates,
+            test_row_data[0]: test_row_data[1],
+            test_row_data[0]: test_row_data[1],
+        }
+        output = functions.extract_all_data(self.test_soup)
+        self.assertDictEqual(expected_output, output)
+        mock_extract_end_dates.assert_called_once_with(self.test_soup)
+        mock_get_all_table_rows.assert_called_once_with(self.test_soup)
+        mock_extract_row_data.assert_has_calls([call(test_relevant_rows[0]), call(test_relevant_rows[1])])
+
+    @patch.object(functions, 'extract_all_data')
+    @patch.object(functions, 'soup_from_url')
+    async def test_get_single_company_fin_stmt(self, mock_soup_from_url, mock_extract_all_data):
+        mock_session = MagicMock()
+        test_ticker, statement = 'bar', BS
+        test_url = f'{BASE_URL}/{test_ticker}/financials{FIN_STMT_URL_SUFFIX[statement]}'
+        mock_soup_from_url.return_value = mock_soup = MagicMock()
+        mock_extract_all_data.return_value = expected_output = {'foo': 'bar'}
+
+        quarterly = False
+        output = await functions.get_single_company_fin_stmt(statement, test_ticker, quarterly, mock_session)
+        self.assertDictEqual(expected_output, output)
+        mock_soup_from_url.assert_called_once_with(test_url, mock_session)
+        mock_extract_all_data.assert_called_once_with(mock_soup)
+        mock_soup_from_url.reset_mock()
+        mock_extract_all_data.reset_mock()
+
+        quarterly = True
+        output = await functions.get_single_company_fin_stmt(statement, test_ticker, quarterly, mock_session)
+        self.assertDictEqual(expected_output, output)
+        mock_soup_from_url.assert_called_once_with(test_url + '/quarter', mock_session)
+        mock_extract_all_data.assert_called_once_with(mock_soup)
+
+    @patch.object(functions, 'get_single_company_fin_stmt')
+    async def test_get_multi_companies_fin_stmt(self, mock_get_single_company_fin_stmt):
+        statement, sym1, sym2, quarterly, mock_session = 'xyz', 'foo', 'bar', False, MagicMock()
+        mock_get_single_company_fin_stmt.return_value = expected_output = 'baz'
+        output = await functions.get_multi_companies_fin_stmt(statement, sym1,
+                                                              quarterly=quarterly, session=mock_session)
+        self.assertEqual(expected_output, output)
+        mock_get_single_company_fin_stmt.assert_called_once_with(statement, sym1, quarterly, mock_session)
+        mock_get_single_company_fin_stmt.reset_mock()
+
+        expected_output = {sym1: expected_output, sym2: expected_output}
+        output = await functions.get_multi_companies_fin_stmt(statement, sym1, sym2,
+                                                              quarterly=quarterly, session=mock_session)
+        self.assertDictEqual(expected_output, output)
+        mock_get_single_company_fin_stmt.assert_has_calls([
+            call(statement, sym1, quarterly, mock_session),
+            call(statement, sym2, quarterly, mock_session)
+        ])
+
+    async def _helper_test_get_any_statement(self, stmt: str, mock_get_multi_companies_fin_stmt):
+        sym1, sym2, quarterly, batch_size, mock_session = 'foo', 'bar', False, 2, MagicMock()
+        mock_get_multi_companies_fin_stmt.return_value = expected_output = 'baz'
+        if stmt == BS:
+            function = functions.get_balance_sheet
+        elif stmt == IS:
+            function = functions.get_income_statement
+        elif stmt == CF:
+            function = functions.get_cash_flow_statement
+        else:
+            raise ValueError
+        output = await function(sym1, sym2, quarterly=quarterly, concurrent_batch_size=batch_size, session=mock_session)
+        self.assertEqual(expected_output, output)
+        mock_get_multi_companies_fin_stmt.assert_called_once_with(
+            stmt, sym1, sym2, quarterly=quarterly, concurrent_batch_size=batch_size, session=mock_session
+        )
+
+    @patch.object(functions, 'get_multi_companies_fin_stmt')
+    async def test_get_balance_sheet(self, mock_get_multi_companies_fin_stmt):
+        await self._helper_test_get_any_statement(BS, mock_get_multi_companies_fin_stmt)
+
+    @patch.object(functions, 'get_multi_companies_fin_stmt')
+    async def test_get_income_statement(self, mock_get_multi_companies_fin_stmt):
+        await self._helper_test_get_any_statement(IS, mock_get_multi_companies_fin_stmt)
+
+    @patch.object(functions, 'get_multi_companies_fin_stmt')
+    async def test_get_cash_flow_statement(self, mock_get_multi_companies_fin_stmt):
+        await self._helper_test_get_any_statement(CF, mock_get_multi_companies_fin_stmt)
+
+    @patch.object(functions, 'get_single_company_fin_stmt')
+    async def test_get_single_company_all_financials(self, mock_get_single_company_fin_stmt):
+        symbol, quarterly, mock_session = 'foo', False, MagicMock()
+        mock_get_single_company_fin_stmt.return_value = bar = 'bar'
+        expected_output = {BS: bar, IS: bar, CF: bar}
+        output = await functions.get_single_company_all_financials(symbol, quarterly, mock_session)
+        self.assertDictEqual(expected_output, output)
+        mock_get_single_company_fin_stmt.assert_has_calls([
+            call(BS, symbol, quarterly, mock_session),
+            call(IS, symbol, quarterly, mock_session),
+            call(CF, symbol, quarterly, mock_session)
+        ])
+
+    @patch.object(functions, 'get_single_company_all_financials')
+    async def test_get_company_financials(self, mock_get_single_company_all_financials):
+        mock_get_single_company_all_financials.return_value = expected_output = 'baz'
+        symbol, quarterly, mock_session = 'foo', False, MagicMock()
+        output = await functions.get_all_financials(symbol, quarterly=quarterly, session=mock_session)
+        self.assertEqual(expected_output, output)
+        mock_get_single_company_all_financials.assert_called_once_with(symbol, quarterly, mock_session)
+        mock_get_single_company_all_financials.reset_mock()
+
+        test_sym1, test_sym2 = 'x', 'y'
+        expected_output = {test_sym1: expected_output, test_sym2: expected_output}
+        output = await functions.get_all_financials(test_sym1, test_sym2,
+                                                    quarterly=quarterly, session=mock_session)
+        self.assertDictEqual(expected_output, output)
+        mock_get_single_company_all_financials.assert_has_calls([
+            call(test_sym1, quarterly, mock_session),
+            call(test_sym2, quarterly, mock_session)
+        ])
+
+    @patch.object(functions, 'ClientSession')
+    async def test_integration_get_company_financials(self, mock_session_cls):
+        mock_session_cls.return_value = mock_session_obj = self.get_mock_session(self.test_html)
+        symbol = 'foo'
+        # Since the web request is mocked we always receive the same HTML markup.
+        expected_output = {
+            BS: {
+                END_DATE: (0, 'End_Date_1', 'End_Date_2'),
+                'foo': (1, 1., -2.),
+                'bar': (2, 2., -3.),
+                'baz': (3, 3., -4.)
+            },
+            IS: {
+                END_DATE: (0, 'End_Date_1', 'End_Date_2'),
+                'foo': (1, 1., -2.),
+                'bar': (2, 2., -3.),
+                'baz': (3, 3., -4.)
+            },
+            CF: {
+                END_DATE: (0, 'End_Date_1', 'End_Date_2'),
+                'foo': (1, 1., -2.),
+                'bar': (2, 2., -3.),
+                'baz': (3, 3., -4.)
+            }
+        }
+        output = await functions.get_all_financials(symbol, session=mock_session_obj)
+        self.assertDictEqual(expected_output, output)
+        mock_session_obj.get.assert_has_calls([
+            call(f'{BASE_URL}/{symbol}/financials{FIN_STMT_URL_SUFFIX[BS]}'),
+            call(f'{BASE_URL}/{symbol}/financials{FIN_STMT_URL_SUFFIX[IS]}'),
+            call(f'{BASE_URL}/{symbol}/financials{FIN_STMT_URL_SUFFIX[CF]}'),
+        ])

tests/test_main.py

@@ -0,0 +1,87 @@
+import logging
+import json
+from unittest import IsolatedAsyncioTestCase
+from unittest.mock import patch
+from argparse import Namespace
+from io import StringIO
+
+from mwfin import __main__ as main_module
+
+
+class MainModuleTestCase(IsolatedAsyncioTestCase):
+
+    @patch.object(main_module.ArgumentParser, 'parse_args')
+    def test_parse_cli(self, mock_parse_args):
+        mock_parse_args.return_value = mock_args = Namespace(foo='a', bar='b')
+        expected_output = vars(mock_args)
+        output = main_module.parse_cli()
+        self.assertDictEqual(expected_output, output)
+
+    def test_configure_logging(self):
+        root_logger = logging.getLogger()
+        root_logger.handlers = []
+        main_module.configure_logging(verbosity=0)
+        self.assertEqual(1, len(root_logger.handlers))
+        self.assertIsInstance(root_logger.handlers[0], logging.StreamHandler)
+        self.assertEqual(logging.CRITICAL, root_logger.level)
+        root_logger.handlers = []
+        main_module.configure_logging(verbosity=1)
+        self.assertEqual(1, len(root_logger.handlers))
+        self.assertIsInstance(root_logger.handlers[0], logging.StreamHandler)
+        self.assertEqual(logging.WARNING, root_logger.level)
+        root_logger.handlers = []
+        main_module.configure_logging(verbosity=2)
+        self.assertEqual(1, len(root_logger.handlers))
+        self.assertIsInstance(root_logger.handlers[0], logging.StreamHandler)
+        self.assertEqual(logging.INFO, root_logger.level)
+        root_logger.handlers = []
+        main_module.configure_logging(verbosity=3)
+        self.assertEqual(1, len(root_logger.handlers))
+        self.assertIsInstance(root_logger.handlers[0], logging.StreamHandler)
+        self.assertEqual(logging.DEBUG, root_logger.level)
+        root_logger.handlers = []
+        main_module.configure_logging(verbosity=9999)
+        self.assertEqual(1, len(root_logger.handlers))
+        self.assertIsInstance(root_logger.handlers[0], logging.StreamHandler)
+        self.assertEqual(logging.DEBUG, root_logger.level)
+
+    @patch.object(main_module, 'get_all_financials')
+    @patch.object(main_module, 'configure_logging')
+    @patch.object(main_module, 'parse_cli')
+    async def test_main(self, mock_parse_cli, mock_configure_logging, mock_get_all_financials):
+        mock_parse_cli.return_value = args = {
+            main_module.VERBOSE: 'foo',
+            main_module.TICKER_SYMBOL: ['bar', 'baz'],
+            main_module.QUARTERLY: 'perhaps',
+            main_module.BATCH_SIZE: 'xyz',
+            main_module.TO_FILE: None,
+            main_module.JSON_INDENT: 42,
+        }
+        mock_get_all_financials.return_value = mock_data = {'data': 'something cool'}
+
+        # To stdout:
+        with patch.object(main_module, 'print') as mock_print:
+            await main_module.main()
+            mock_parse_cli.assert_called_once_with()
+            mock_configure_logging.assert_called_once_with(args[main_module.VERBOSE])
+            mock_get_all_financials.assert_awaited_once_with(*args[main_module.TICKER_SYMBOL],
+                                                             quarterly=args[main_module.QUARTERLY],
+                                                             concurrent_batch_size=args[main_module.BATCH_SIZE])
+            mock_print.assert_called_once_with(json.dumps(mock_data, indent=args[main_module.JSON_INDENT]))
+        mock_parse_cli.reset_mock()
+        mock_configure_logging.reset_mock()
+        mock_get_all_financials.reset_mock()
+
+        # To file:
+        args[main_module.TO_FILE] = 'some_file'
+        with patch.object(main_module, 'open') as mock_open:
+            mock_open.return_value.__enter__.return_value = mock_file = StringIO()
+            await main_module.main()
+            mock_parse_cli.assert_called_once_with()
+            mock_configure_logging.assert_called_once_with(args[main_module.VERBOSE])
+            mock_get_all_financials.assert_awaited_once_with(*args[main_module.TICKER_SYMBOL],
+                                                             quarterly=args[main_module.QUARTERLY],
+                                                             concurrent_batch_size=args[main_module.BATCH_SIZE])
+            expected_contents = json.dumps(mock_data, indent=args[main_module.JSON_INDENT])
+            mock_file.seek(0)
+            self.assertEqual(expected_contents, mock_file.read())

tests/test_structure.html

@@ -0,0 +1,49 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Title</title>
+</head>
+<body>
+    <div class="financials">
+        <header>
+            <h2><span>Foo table</span></h2>
+            <small> All values USD.</small>
+        </header>
+        <div>
+            <div>
+                <table>
+                    <thead>
+                        <tr>
+                            <th><div class="xyz abc"> !!Item </div><div> !!Item </div></th>
+                            <th><div> End_Date_1 </div></th>
+                            <th><div> End_Date_2 </div></th>
+                            <th></th>
+                        </tr>
+                    </thead>
+                    <tbody>
+                        <tr>
+                            <td><div class="xyz indent--small"> foo </div><div> foo </div></td>
+                            <td></td>
+                            <td></td>
+                            <td><div> <div data-chart-data="1.0,-2.0"><div></div></td>
+                        </tr>
+                        <tr>
+                            <td><div class="xyz indent--medium"> bar </div><div> bar </div></td>
+                            <td></td>
+                            <td></td>
+                            <td><div> <div data-chart-data="2.0,-3.0"><div></div></td>
+                        </tr>
+                        <tr>
+                            <td><div class="xyz indent--large"> baz </div><div> baz </div></td>
+                            <td></td>
+                            <td></td>
+                            <td><div> <div data-chart-data="3.0,-4.0"><div></div></td>
+                        </tr>
+                    </tbody>
+                </table>
+            </div>
+        </div>
+    </div>
+</body>
+</html>