- 前言
- python2
- python3
最近使用python写了一个比较大的程序发现，不同的元素占用空间都很大，且python2和python3不一样，列举在下面
python2空链表72字节，空字典280字节，空集合232字节，None16字节，char38字节, int绝对值在现在的ns时间戳范围内都是24字节；
Python 2.7.16 (default, Sep 6 2021, 07:39:44)
[GCC Apple LLVM 12.0.5 (clang-1205.0.19.59.6) [+internal-os, ptrauth-isa=deploy on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.getsizeof(1636943622)
24
>>> sys.getsizeof(1636943622000)
24
>>> sys.getsizeof(1636943622000000)
24
>>> sys.getsizeof(1636943622000000000)
24
>>> sys.getsizeof(1736943622000000000)
24
>>> sys.getsizeof(-1736943622000000000)
24
>>> sys.getsizeof([])
72
>>> sys.getsizeof(None)
16
>>> sys.getsizeof({})
280
>>> sys.getsizeof(set())
232
python3
空链表56字节，空字典64字节，空集合216字节，None16字节，char50字节，0是24字节，除0外常见的int为28字节，秒，毫秒，微秒级别的时间戳都是32字节，纳秒级别时间戳是36字节;
Python 3.9.6 (default, Jun 29 2021, 05:25:02)
[Clang 12.0.5 (clang-1205.0.22.9)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.getsizeof(0)
24
>>> sys.getsizeof(1)
28
>>> sys.getsizeof(-1)
28
>>> sys.getsizeof(1636943622)
32
>>> sys.getsizeof(1636943622000)
32
>>> sys.getsizeof(1636943622000000)
32
>>> sys.getsizeof(1636943622000000000)
36
>>> sys.getsizeof(-1636943622000000000)
36
>>> sys.getsizeof(-1736943622000000000)
36
>>> sys.getsizeof([])
56
>>> sys.getsizeof({})
64
>>> sys.getsizeof(set())
216
>>> sys.getsizeof(None)
16
python中不要轻易将默认值设成空list，空字典，空集合，而应是None，另外实在要节约空间，还是不要用python了吧
