Perform a safe dictionary lookup with a fallback default value.

Provide a default value when a dictionary key might be missing, avoiding KeyError exceptions.

When accessing dictionary entries where the key may not be present and a default value is desired instead of raising an exception.

Used in data processing, configuration lookup, caching, or any scenario where dictionary lookups may fail.

dict.get(key, default)

object.method(key, default)

my_dict: any mapping object; key: hashable key; default: any value to return if key is missing

• dict
• key
• default
• None
• 0
• empty string

• dict[key] if key in dict else default
• dict.setdefault(key
• default)

Using dict[key] without checking leads to KeyError; forgetting to provide a default results in None being returned unintentionally

dict.setdefault(key, default) also sets the key if missing; dict.pop(key, default) removes and returns the key

Coming from Java: Map.get returns null for missing keys, leading to expecting None instead of providing a default; Coming from JavaScript: obj[key] returns undefined for missing keys, so developers may forget to supply a default and unintentionally receive None.

• dictionary access patterns

The default is returned only when the key is absent; if the key exists with a falsy value (e.g., 0, ''), that value is returned, not the default.

Provides a concise, safe way to handle missing keys, improving code robustness and readability.

Think 'get or default'.

Note that dict.get does not insert the key into the dictionary; use dict.setdefault if insertion of the default value is desired.

Using dict.setdefault to both retrieve and set default, or using collections.defaultdict for automatic defaults.