Btukfyl

I'm new to pandas, trying to create a new column in Pandas Dataframe, and assign a string value based on a function, but the outcome outputs only 1 value ('residential) to all 5,000 columns. Any idea what's wrong with my code? Thank you

def programType(c):

if c['Primary Property Type - Self Selected'] == 'Multifamily Housing' or 'Residence Hall/Dormitory':

    return 'Residential'



elif c['Primary Property Type - Self Selected'] == 'Bank Branch' or 'Hotel' or 'Financial Office' 

or 'Retail Store' or 'Distribution Center' or 'Non-Refrigerated Warehouse' or 'Fitness Center/Health Club/Gym' 

or 'Mixed Use Property' or 'Self-Storage Facility' or 'Wholesale Club/Supercenter' or 'Supermarket/Grocery Store':

    return 'Commercial'  



elif c['Primary Property Type - Self Selected'] == 'Senior Care Community' or 'K-12 School' or 'College/University' 

or 'Worship Facility' or 'Medical Office' or 'Hospital (General Medical & Surgical)':

    return 'Institutional'



elif c['Primary Property Type - Self Selected'] == 'Manufacturing/Industrial Plant': 

    return 'Industrial'



else:

    return 'Other'

The new column is called 'Program Type'

datav3['Program Type'] = datav3.apply(programType, axis=1)

In pandas is best avoid loops (apply are loops under the hood) if exist vectorized solutions, because loops are slow.

I try rewrite your code - create dictionary with output and list of values, swap keys with values and call map, last for not matched values add fillna:

d = {'Residential' :['Multifamily Housing', 'Residence Hall/Dormitory'],

     'Commercial' : ['Bank Branch', 'Hotel' , 'Financial Office' , 'Retail Store', 'Distribution Center', 

                   'Non-Refrigerated Warehouse', 'Fitness Center/Health Club/Gym', 'Mixed Use Property',

                   'Self-Storage Facility', 'Wholesale Club/Supercenter', 'Supermarket/Grocery Store'],

     'Institutional':['Senior Care Community', 'K-12 School', 'College/University', 'Worship Facility',

                     'Medical Office', 'Hospital (General Medical & Surgical)'],

     'Industrial':  ['Manufacturing/Industrial Plant'] }

d1 = {k: oldk for oldk, oldv in d.items() for k in oldv}

print (d1)



{

    'Multifamily Housing': 'Residential',

    'Residence Hall/Dormitory': 'Residential',

    'Bank Branch': 'Commercial',

    'Hotel': 'Commercial',

    'Financial Office': 'Commercial',

    'Retail Store': 'Commercial',

    'Distribution Center': 'Commercial',

    'Non-Refrigerated Warehouse': 'Commercial',

    'Fitness Center/Health Club/Gym': 'Commercial',

    'Mixed Use Property': 'Commercial',

    'Self-Storage Facility': 'Commercial',

    'Wholesale Club/Supercenter': 'Commercial',

    'Supermarket/Grocery Store': 'Commercial',

    'Senior Care Community': 'Institutional',

    'K-12 School': 'Institutional',

    'College/University': 'Institutional',

    'Worship Facility': 'Institutional',

    'Medical Office': 'Institutional',

    'Hospital (General Medical & Surgical)': 'Institutional',

    'Manufacturing/Industrial Plant': 'Industrial'

}

datav3 = pd.DataFrame({'Program':['Medical Office','Hotel',

                                       'Residence Hall/Dormitory',

                                       'Manufacturing/Industrial Plant','House']})

datav3['Program Type'] = datav3['Program'].map(d1).fillna('Other')

print (datav3)

                          Program   Program Type

0                  Medical Office  Institutional

1                           Hotel     Commercial

2        Residence Hall/Dormitory    Residential

3  Manufacturing/Industrial Plant     Industrial

4                           House          Other

The issue is with your if loops. The way you are comparing after or is not correct.

Writing or 'Residence Hall/Dormitory' will always be true, hence, only the first if gets evaluated everytime and you get Residential in all rows.

Instead of this:

if c['Primary Property Type - Self Selected'] == 'Multifamily Housing' or 'Residence Hall/Dormitory':

Do this:

if c['Primary Property Type - Self Selected'] == 'Multifamily Housing' or c['Primary Property Type - Self Selected'] == 'Residence Hall/Dormitory':

OR

if any([c['Primary Property Type - Self Selected'] == 'Multifamily Housing', c['Primary Property Type - Self Selected'] == 'Residence Hall/Dormitory']):

Just make the above change, and your code should do what is expected. Hope this is clear.