利用Python内置函数id()找出内部地址,探讨赋值与内建地址. id()的官方解释:this is the address of the object in memory 那么 a =1 是什么意思? >>> id(1)1539072224>>> =============================== RESTART: Shell ===============================>>> id(1)1539072224 int…
If you played with the fibonacci function from Section 6.7, you might have noticed thatthe bigger the argument you provide, the longer the function takes to run. Furthermore,the run time increases very quickly.To understand why, consider Figure 11.2,…
Python’s handling of default parameter values is one of a few things that tends to trip up most new Python programmers (but usually only once). What causes the confusion is the behaviour you get when you use a “mutable” object as a default value; tha…
""" The main QuerySet implementation. This provides the public API for the ORM. """ import copy import sys import warnings from collections import OrderedDict, deque from django.conf import settings from django.core import ex…