Convert numerical data to categorical in Python

Question

I have a pandas dataframe with the column fert_Rate for fertility rate. I want to have a new column with these values as categorical instead of numerical. Instead of 1.0, 2.5, 4.0 I want something like (low, medium, high). In R I would have written something like this:

attach(mydata)
mydata$fertcat[fert_Rate > 3.5] <- "High"
mydata$fertcat[fert_Rate > 2 & fert_Rate <= 3.5] <- "Medium"
mydata$fertcat[fert_Rate <= 2] <- "Low"
detach(mydata)

Is there a similar way to do it in python or should I just loop over the column to create?

Answer 1

Use pd.cut to bin your data.

df = pd.DataFrame({'fert_Rate': [1, 2, 3, 3.5, 4, 5]})
>>> df.assign(fertility=pd.cut(df['fert_Rate'], 
                               bins=[0, 2, 3.5, 999], 
                               labels=['Low', 'Medium', 'High']))
   fert_Rate fertility
0        1.0       Low
1        2.0       Low
2        3.0    Medium
3        3.5    Medium
4        4.0      High
5        5.0      High