Dictionaries

Dictionaries store key-value pairs. Keys can be any hashable value: strings, numbers, booleans, None, or tuples made only of hashable values. String keys are the most common for game data:

data = {"name": "Crystal", "value": 300}
empty = dict()

Access and modify:

print(data["name"])       # Crystal
data["quality"] = "high"

coords = {}
coords[(0, 0)] = "base"

Check if a key exists:

if "name" in data:
  print(data["name"])

Iterate:

for key in data.keys():
  print(key, data[key])

for pair in data.items():
  key = pair[0]
  val = pair[1]
  print(f"{key}: {val}")

Merge

Use left | right to make a new merged dictionary. Use left |= right to update the existing dictionary in place. When the same key appears in both, the right-hand value wins.

thing = {"a": 1, "b": 2}
other = {"a": 3, "c": 4}
print(thing | other) # {"a": 3, "b": 2, "c": 4}

Methods

Method	Purpose
.keys()	list of all keys
.values()	list of all values
.items()	list of [key, value] pairs
.get(key, default)	get value or default if missing
.has(key)	check if key exists
.pop(key, default)	remove key and return value
.popitem()	remove and return the last inserted [key, value] pair
.update(dict)	merge another dict in
.setdefault(key, default)	get or set default
.clear()	remove all entries

See also

• dict: the complete built-in type reference