tessa.price.yahoo

 1"""Everything Yahoo-Finance-related (other than search)."""
 2
 3import pandas as pd
 4import yfinance as yf
 5from yfinance.exceptions import YFRateLimitError
 6from .types import PriceHistory, RateLimitHitError
 7
 8# Ensure yfinance raises exceptions instead of silently failing
 9yf.config.debug.hide_exceptions = False
10
11START_FROM = "2000-01-01"
12"""Adjust this date if you need to get historical data further in the past. Note that
13extending this date will lead to increased load on the Yahoo Finance servers.
14"""
15
16
17def get_price_history(
18    query: str, currency_preference: str = "USD"  # pylint: disable=unused-argument
19) -> PriceHistory:
20    """Get price history for a given query. Note that `currency_preference` will be
21    ignored since Yahoo Finance returns each ticker in the one currency that is set for
22    that ticker.
23    """
24    try:
25        ticker = yf.Ticker(query)
26        df = ticker.history(start=START_FROM)
27    except YFRateLimitError as exc:
28        raise RateLimitHitError(source="yahoo") from exc
29
30    # Simplify dataframe:
31    df = df.copy()
32    df = df[["Close"]]
33    df.index = pd.to_datetime(df.index, utc=True)
34    df.index.name = "date"
35    df.rename(columns={"Close": "close"}, inplace=True)
36
37    return PriceHistory(df, ticker.get_history_metadata()["currency"])