Is there a way to have a default value inside a dictionary in Python?

user_11438319 0
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I want to know if there is a way to have a default value in a dictionary (without using the get function), so that:

dict colors = {
"Black":(0, 0, 0),
"White":(255, 255, 255),
default:(100, 100, 100)
};

paint(colors["Blue"]);  # Paints the default value (Grey) onto the screen

Of course, the code above wouldn't work in Python, and I have serious doubt it is even possible.

I Know that by using get I could do this easily, however I'm still curious if there is any other way (just for curiosity).

dictionary python
2 Answers

You can use a defaultdict.

from collections import defaultdict

colors = defaultdict(lambda: (100, 100, 100))

colors["Black"] = (0, 0, 0),
colors["White"] = (255, 255, 255)

# Prints (0, 0, 0), because "Black" is mapped to (0, 0, 0) in the dictionary.
print(colors["Black"]) 

# Prints (100, 100, 100), because "Blue" is not a key in the dictionary.
print(colors["Blue"])
user_177698150

Check out the collections.defaultdict type (https://docs.python.org/3/library/collections.html#collections.defaultdict):

The first argument provides the initial value for the default_factory attribute; it defaults to None. All remaining arguments are treated the same as if they were passed to the dict constructor, including keyword arguments.

Your code would use it like this:

from collections import defaultdict

colors = defaultdict(lambda: (100, 100, 100), {
    "Black":(0, 0, 0),
    "White":(255, 255, 255),
})

print(colors['Blue'])
user_28320110
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