Course Content
Data Manipulation using pandas
Data Manipulation using pandas
2. Preprocessing Data: Part II
Poor Data Presentation
One of the reasons that can cause types inconsistency may be poor data presentation. For instance, values of weight column may have also the measurment unit (like, 25kg, 14lb). In this case Python will understand these values as strings.
Let's see what is wrong with the values in the columns we considered to have wrong type.
We found the root of the problem. All the columns but 'totinch'
use dots .
as indicator for missing values, while values in the 'totinch'
column use commas ,
as the decimal separator. This may happen due to data origin, for instance. This problem can be solved by replacing commas with dots, and converting to float
type.
Note, if you try to convert existing values into numeric type, then the error
ValueError
will be raised.
Everything was clear?