how to convert categorical variable into numeric in python code example

Example 1: how to convert contionous data into categorical data in python

pd.cut(df.Age,bins=[0,2,17,65,99],labels=['Toddler/Baby','Child','Adult','Elderly'])
# where bins is cut off points of bins for the continuous data 
# and key things here is that no. of labels is always less than 1

Example 2: how to separate numeric and categorical variables in python

df.loc[:,df.dtypes==np.object]

Example 3: how to convert categorical data to numerical data in python

import pandas as pd
import numpy as np

# Define the headers since the data does not have any
headers = ["symboling", "normalized_losses", "make", "fuel_type", "aspiration",
           "num_doors", "body_style", "drive_wheels", "engine_location",
           "wheel_base", "length", "width", "height", "curb_weight",
           "engine_type", "num_cylinders", "engine_size", "fuel_system",
           "bore", "stroke", "compression_ratio", "horsepower", "peak_rpm",
           "city_mpg", "highway_mpg", "price"]

# Read in the CSV file and convert "?" to NaN
df = pd.read_csv("https://archive.ics.uci.edu/ml/machine-learning-databases/autos/imports-85.data",
                  header=None, names=headers, na_values="?" )
df.head()