Boolean indexing

We use Boolean indexing to filter or select parts of the data. The operators are as follows:

These operators must be grouped using parentheses when used together. Using the earlier DataFrame from the previous section, here we display the trading dates for which NASDAQ closed above 4,300:

  In [311]: sharesIndexDataDF.ix[(sharesIndexDataDF['PriceType']=='close') & \
                         (sharesIndexDataDF['Nasdaq']>4300) ]
  Out[311]:        PriceType  Nasdaq   S&P 500   Russell 2000
      TradingDate
      2014/02/27   close  4318.93   1854.29   1187.94
      2014/02/28   close  4308.12   1859.45   1183.03
      2 rows × 4 columns
  

You can also create Boolean conditions in which you use arrays to filter out parts of the data, as shown in the following...