Python:DataModel

lastmod 2025-04-25created 2020-10-208 edits

Special method names

• 3. Data model — Python 3.10.6 documentation # 3.3. Special method names
• (Translation) Python's Magic Methods | ziwon.github.io

A class can implement certain operations that are invoked by special syntax (such as arithmetic operations or subscripting and slicing) by defining methods with special names.

Things like __new__, __add__ ...

str

• (Python) Looking at the difference between str and repr

slots

• 10. slots Magic
• Stackoverflow - Usage of slots?
• [Recommended] Advanced Python features | GeekNews
  • [Original] 14 Advanced Python Features | Edward Li's Blog [^0]

However, for small classes with known attributes, it can become a bottleneck. The dict type wastes a lot of memory. Python cannot allocate a fixed amount of memory at object creation to store all the attributes. So creating a large number of objects wastes a lot of RAM. There is a way to work around this problem. Using __slots__ tells Python not to use the dict type and to allocate memory only for a fixed set of attributes.

class MyClass(object):
    __slots__ = ('name', 'class')

    def __init__(name, class):
        self.name = name
        self.class = class
        self.set_up()
    # ...

enter/exit

See Python:With for details.

See also

• Python

Favorite site

• 3. Data model — Python 3.9.0 documentation