Why would I use `dict.update()` in Python instead of assigning values directly?

General Discussions
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1

I understand that the update() method on dictionaries in Python can be used to add new key-value pairs or update existing ones. For example:

my_dict = {'1': 11, '2': 1445}
my_dict.update({'1': 645, 5: 123})

This will result in:

{'1': 645, '2': 1445, 5: 123}

But I can also achieve the same effect by directly assigning values:

my_dict['1'] = 645
my_dict[5] = 123

This also gives:

{'1': 645, '2': 1445, 5: 123}

So I’m wondering, in what situations is python dict update crucial or more beneficial than just assigning values manually? Are there practical cases where update() is the preferred approach?

2

I usually use update() when I have multiple key-value pairs to add or modify at once. It keeps your code clean instead of writing several assignments:

my_dict.update({'a': 1, 'b': 2, 'c': 3})

Much neater than doing my_dict[‘a’]=1; my_dict[‘b’]=2; …

3

Another case: merging dictionaries. If you have two dictionaries, update() is perfect:

dict1.update(dict2)

All keys from dict2 are added or overwrite existing ones. Doing this with individual assignments would be cumbersome.

4

From my experience, update() is handy for dynamic updates, like updating configuration dictionaries from user input or files. It’s safer and more readable than looping through keys manually.