The Airline column has extra punctuation/symbols around the names. Pull out just the airline name (e.g. '(British Airways. )' → 'British Airways'). Return the cleaned Airline Series.

Input

            From_To  FlightNumber  RecentDelays              Airline
0      LoNDon_paris       10045.0      [23, 47]               KLM(!)
1      MAdrid_miLAN           NaN            []    <Air France> (12)
2  londON_StockhOlm       10065.0  [24, 43, 87]  (British Airways. )
3    Budapest_PaRis           NaN          [13]       12. Air France
4   Brussels_londOn       10085.0      [67, 32]          "Swiss Air"

Output

0                KLM
1         Air France
2    British Airways
3         Air France
4          Swiss Air
Name: Airline, dtype: object