python3-built-in data types-mapping types

Types of mappings in Python3

1. There is currently only one standard mapping type-dictionary Dict

2. Dictionaries are mutable objects that store data in the form of key-value pairs

3. The key of the dictionary must be a value of immutable type (such as list, dictionary, etc.), and cannot be duplicated (repeated overrides)

4. The value of the dictionary is almost arbitrary and can be repeated

5. Although floating-point numbers can be used as keys, it is strongly not recommended (because the computer stores the approximate values of floating-point numbers), it is recommended to use a string as the key

python3-built-in data types-mapping types