fix ruff

yfinance/base.py

@@ -22,14 +22,12 @@
 from __future__ import print_function
 
 import json as _json
-import re
 import warnings
 from io import StringIO
 from typing import Optional, Union
 from urllib.parse import quote as urlencode
 
 import pandas as pd
-import pytz
 import requests
 
 from . import utils, cache
@@ -612,13 +610,13 @@ def get_ticker_tz():
         # Try to remap all ambiguous timezone values:
         tzinfo['TZ'] = tzinfo['TZ'].str.replace('BST', 'Europe/London')
         tzinfo['TZ'] = tzinfo['TZ'].str.replace('GMT', 'Europe/London')
-        if not '.' in self.ticker:
+        if '.' not in self.ticker:
             tzinfo['TZ'] = tzinfo['TZ'].str.replace('EST', 'America/New_York')
         elif self.ticker.endswith(".AX"):
             tzinfo['TZ'] = tzinfo['TZ'].str.replace('EST', 'Australia/Sydney')
         tzinfo['TZ'] = tzinfo['TZ'].str.replace('MST', 'America/Denver')
         tzinfo['TZ'] = tzinfo['TZ'].str.replace('PST', 'America/Los_Angeles')
-        if not '.' in self.ticker:
+        if'.' not in self.ticker:
             tzinfo['TZ'] = tzinfo['TZ'].str.replace('CST', 'America/Chicago')
         else:
             # Revisit if Cuba get a stock exchange