関連ワード:  python get first element in dataframe    python get first row in dataframe    python get first value in dataframe    python get first column in dataframe    python select first row in dataframe    python get first value in dataframe column    python get first item in dataframe    python get index of first row in dataframe    python get first element of dataframe column    python get first row of pandas dataframe  
結果 : python get first element in dataframe