O'Reilly logo

Mastering pandas by Femi Anthony

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Boolean indexing

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

Operators

Symbol

OR

|

AND

&

NOT

~

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 the NASDAQ closed above 4300:

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:

In [316]: highSelection=sharesIndexDataDF['PriceType']=='high' ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required