Course Content
Data Manipulation using pandas
Data Manipulation using pandas
2. Preprocessing Data: Part II
Replacing Specific Elements
The next step we need to do is to replace dots. This task is a bit harder than the previous one, since you will replace only specific elements.
First, let's remind how to select specific rows and columns based on some condition. It can be done by applying the .loc[]
property. The first parameter is either row numbersm, or condition; the second one is column names. For instance, let's get the rows containing only dot characters .
within the 'morgh'
column.
Since we accessed the necessary rows, we can easily replace them by reassigning. We are going to repalce all the dots by NA
values (nan
from NumPy
) and then convert the resulting column to float
type (NA
doesn't support int
type, float
only).
As you can see, the column is now considered to have float
type, which means you can apply numerical methods to it (i.e., you can calculate mean, min, max, etc.).
Everything was clear?