searching through strings using pandas dataframes

lutzy.py

import pandas as pd


df = pd.DataFrame(
        {
                'ticker':
                    [
                            'AAPL',
                            'SPY',
                            'A',
                            'GP',
                            'NFLX',
                            'SPY',
                            'FB',
                            'CPI',
                            'SNAP'
                    ],
                'allowed_tickers':
                    [
                            'BA;AAPL;TLT',
                            'SPY;GS',
                            'AAA;AA;AAPL',
                            'GS;GP',
                            'TLT;SPY;GS;NFLX;AAA;FB',
                            'BA;AAPL;TLT;QQQ;SPY',
                            'SPY;GS;NFLX;AAA;SNAP',
                            'AAPL;TLT;SPY;GS;NFLX',
                            'SPY;GS;NFLX;SNAP'
                    ]
        }
)

check = ['Allowed' if (";" + df['ticker'][i] + ";") in df['allowed_tickers'][i] or (
        (df['ticker'][i] + ";") in df['allowed_tickers'][i] and df['allowed_tickers'][i].find((df['ticker'][i] + ";")) == 0) or (
                              (";" + df['ticker'][i]) in df['allowed_tickers'][i] and df['allowed_tickers'][i].find(
                              (";" + df['ticker'][i])) == len(df['allowed_tickers'][i]) - len((";" + df['ticker'][i]))) or len(
        df['allowed_tickers'][i]) == len((df['ticker'][i])) else '***INVALID TICKER***' for i in range(len(df['ticker']))]

df['validation'] = check
df