Identifying empty list in JSON data in Python

August 4, 2022

I have a json data set I’m trying to insert into a database. To do so, I need placeholders "" for non-existent data. In the example below, if there’s no email address, I need the insert statement to be (….,"boo",….) instead of (….,"me@mail.com",….). I have tried checking for list length, using not, email == [], etc. Every way I know how or have Googled, and none are working.

Example data:

{
    "data": [
        {
            "campsites": {
                ...
            },
            "contacts": {
                "emailAddresses": [],
                "phoneNumbers": []
            },
...

My code for this particular section:

results = response.json()['data']
for item in results:
    for email in item['contacts']['emailAddresses']:
        if email == []:
            print("boo")
        else:
            print(email['emailAddress'])

The if statement (regardless of how I’ve tried so far), does not execute, and I get a printed list of only the email addresses if they exist:

GRSM_Smokies_Information@nps.gov
CATO_superintendent@nps.gov
dyanna.threeirons@crow-nsn.gov
ozar_campground_operation@nps.gov
orpi_information@nps.gov
ozar_campground_operations@nps.gov
biso_information@nps.gov
chis_information@nps.gov
info@antelopepointmarina.com

I need:

boo
GRSM_Smokies_Information@nps.gov
CATO_superintendent@nps.gov
dyanna.threeirons@crow-nsn.gov
ozar_campground_operation@nps.gov
orpi_information@nps.gov
ozar_campground_operations@nps.gov
biso_information@nps.gov
boo
chis_information@nps.gov
info@antelopepointmarina.com

>Solution :

If the list of "emailAddresses" is empty, the for loop doesn’t get executed. Accordingly print("boo") neither.

You need to check the list first, before iterate through the list:

results = response.json()["data"]
for item in results:
    emails = item["contacts"]["emailAddresses"]
    if emails:
        for email in emails:
            print(email)
    else:
        print("boo")