Assuming connectionDetails is a Python dictionary, how can this be optimized to efficiently handle a default value for a Python dictionary?

General Discussions
1

What is the most elegant and “Pythonic” way to refactor code for checking if a key exists in a dictionary and assigning a default value if it’s missing?

Assuming connectionDetails is a Python dictionary, how can this be optimized to efficiently handle a default value for a Python dictionary?

2

Hi,

You can use dict.get() method.

host = connectionDetails.get('host', someDefaultValue)

This is the most common and “pythonic” way to handle a python dictionary default value. The get() method checks for the key ‘host’ and returns its value if found; otherwise, it returns someDefaultValue.

3

You can also use setdefault() method.

host = connectionDetails.setdefault('host', someDefaultValue)

The setdefault() method checks if ‘host’ exists in the dictionary. If it does, it returns its value. Otherwise, it sets ‘host’ to someDefaultValue in the dictionary and then returns the default value.

4

You can also use if-else in a single line:

host = connectionDetails['host'] 
if 'host' in connectionDetails 
else someDefaultValue

This inline conditional approach achieves the same result but is slightly less concise compared to get() while still ensuring a python dictionary default value.