df['ColumnA']: Series - Selects ColumnA from DataFrame df

df[['ColumnA', 'ColumnB']]: DataFrame - Selects ColumnA and ColumnB from DataFrame df

DataFrame.loc[index: number | string]: Series - Returns the row at index

DataFrame.loc[index: number | string, column: string]: any - Returns the value at index and column column

DataFrame.iloc[i: number]: Series - Returns the row at position i

df[(df['W'] > 0) & (df['X'] > 1)] - Return new data frame where column W is greater than 0 and X is greater than 1