Linear regression analysis with string/categorical features (variables)?

Question

Regression algorithms seem to be working on features represented as numbers. For example:

This data set doesn\'t contain categorical features/variables. It

Answer 1

One way to achieve regression with categorical variables as independent variables is as mentioned above - Using encoding. Another way of doing is by using R like statistical formula using statmodels library. Here is a code snippet

from statsmodels.formula.api import ols
tips = sns.load_dataset("tips")

model = ols('tip ~ total_bill + C(sex) + C(day) + C(day) + size', data=tips)
fitted_model = model.fit()
fitted_model.summary()

Dataset

total_bill  tip     sex  smoker day  time  size
0   16.99   1.01    Female  No  Sun Dinner  2
1   10.34   1.66    Male    No  Sun Dinner  3
2   21.01   3.50    Male    No  Sun Dinner  3
3   23.68   3.31    Male    No  Sun Dinner  2
4   24.59   3.61    Female  No  Sun Dinner  4

Summary of regression