KnowCardPython · Dictionaries & Sets
What does dict.fromkeys(["a", "b", "c"], 0) build, and what's the trap when the default value is mutable?
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More in Dictionaries & Sets
What does this print?
```
d = {"a": 1, "a": 2}
print(d)
```
Why does this raise an error?
```
d = {[1, 2]: "x"}
```
Can a tuple be a dict key but a list cannot? Why the difference?
What does this print?
```
d = {1: "x"}
print(d[1.0])
```
What does this print?
```
d = {"a": 1, "b": 2}
print("a" in d)
print(1 in d)
```
What does this loop print?
```
d = {"a": 1, "b": 2}
for x in d:
print(x)
```
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