cut() ref

Simple cut

footprintBins = [0, 500, 750, 1000, 1500, 10000, 100000]

df_building['footprintClass'] = pd.cut(
    df_building.footprintPerUnit, footprintBins)

Cut with custom labels; convert resulting category to string

storeyClassBins_aptHi = [4, 14, 24, 999]
storeyClassBins_aptHi_labels = ['5To14Storey', '15To24Storey', '25AndUpStorey']

df_aptByP_Hi_bldgMatch['storeysClass'] = pd.cut(
    df_aptByP_Hi_bldgMatch.numStoreys_est, storeyClassBins_aptHi,
    labels=storeyClassBins_aptHi_labels)
df_aptByP_Hi_bldgMatch['storeysClass'] = \
    df_aptByP_Hi_bldgMatch['storeysClass'].astype(str)