Check if path in json object exists?

Question

I am currently doing something like this to access an array in my json object

teacher_topical_array = teacher_obj["medication"]["topical"]

However before doing that I would like to make sure the path teacher_obj["medication"]["topical"] exists and I am looking for a simpler approach to accomplish this.

Now I understand I could do something like this

if "medication" in teacher_obj:
    if "topical" in teacher_obj["medication"]:
             #yes the key exists

I wanted to know if I could accomplish the above in a different way. That might be more effective if I had to check for something like

teacher_obj["medication"]["topical"]["anotherkey"]["someOtherKey"]

You can use exception handling `try: teacher_obj["medication"]["topical"]["anotherkey"]["someOtherKey"] except KeyError: ...`. — DYZ, Aug 03 '17 at 00:32
@SnakesandCoffee Woah. The linked dupe has a similar answer to mine. — cs95, Aug 03 '17 at 00:33

score 7 · Accepted Answer · answered Aug 03 '17 at 00:33

7

The LYBL approach: Chain get calls, if you don't want to use try-except braces...

teacher_topical_array = teacher_obj.get("medication", {}).get("topical", None)

The EAFP approach: Use a try-except block and catch a KeyError.

try:
    teacher_topical_array = teacher_obj["medication"]["topical"]
except KeyError:
    teacher_topical_array = []

answered Aug 03 '17 at 00:33

cs95

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I like the LYBL approach will go with that – James Franco Aug 03 '17 at 00:40

Check if path in json object exists?

1 Answers1