What is it

Dictionaries are used to store data values in key:value pairs.

dict = { 
  "brand": "Ford", 
  "model": "Mustang",
  "year": 1964 
}

Values can be referred using the key name.

dict = { 
  "brand": "Ford", 
  "model": "Mustang", 
  "year": 1964 
}

print(dict["brand"]) # Ford

Mutating Dictionary Entries

Setting key to value.

dictionary[key] = value

Deleting a key:value pair.

• Raises KeyError if key is not in the dictionary.

del dictionary[key]

Index Reference, Sort Order, and Duplicate Entries

Dictionaries are unordered.

Dictionary items CAN'T be referenced by an index.

Duplicate value assignment of a same key will override existing entries.

In below example, setting year key twice will take the latter value of 2020 over earlier assigned valued of 1964.

dict = { 
  "brand": "Ford",
  "model": "Mustang", 
  "year": 1964, 
  "year": 2020 
}

print(dict)
# {
#   'brand': 'Ford',
#   'model': 'Mustang',
#   'year': 2020
# }