Python sys.getsizeof()详解 - 内存占用测量与优化完整指南

import sys

sys.getsizeof(object[, default])

import sys

# 数值类型
print("数值类型:")
print(f"  int(0): {sys.getsizeof(0)} 字节")
print(f"  int(1): {sys.getsizeof(1)} 字节")
print(f"  int(10**6): {sys.getsizeof(10**6)} 字节")
print(f"  float(1.0): {sys.getsizeof(1.0)} 字节")
print(f"  bool(True): {sys.getsizeof(True)} 字节")
print(f"  None: {sys.getsizeof(None)} 字节")

# 字符串类型
print("\n字符串类型:")
print(f"  '': {sys.getsizeof('')} 字节")
print(f"  'a': {sys.getsizeof('a')} 字节")
print(f"  'abc': {sys.getsizeof('abc')} 字节")
print(f"  '你好': {sys.getsizeof('你好')} 字节")

# 容器类型（仅计算容器本身，不含元素内容）
print("\n容器类型（空容器）:")
print(f"  []: {sys.getsizeof([])} 字节")
print(f"  (): {sys.getsizeof(())} 字节")
print(f"  {{}}: {sys.getsizeof({})} 字节")
print(f"  set(): {sys.getsizeof(set())} 字节")

数值类型:
  int(0): 24 字节
  int(1): 28 字节
  int(10**6): 28 字节
  float(1.0): 24 字节
  bool(True): 28 字节
  None: 16 字节

字符串类型:
  '': 49 字节
  'a': 50 字节
  'abc': 52 字节
  '你好': 53 字节

容器类型（空容器）:
  []: 56 字节
  (): 40 字节
  {}: 64 字节
  set(): 216 字节

import sys

def track_list_growth():
    """跟踪列表增长时的内存变化"""
    lst = []
    sizes = []

    for i in range(20):
        size = sys.getsizeof(lst)
        sizes.append((len(lst), size))
        lst.append(i)

    print("列表长度 -> 内存大小 (字节)")
    print("-" * 35)
    for length, size in sizes:
        bar = '#' * (size // 10)
        print(f"  {length:2d} -> {size:4d}  {bar}")

track_list_growth()

列表长度 -> 内存大小 (字节)
-----------------------------------
   0 ->   56
   1 ->   88  ########
   2 ->   88  ########
   3 ->   88  ########
   4 ->   88  ########
   5 ->  120  ###########
   6 ->  120  ###########
   7 ->  120  ###########
   8 ->  120  ###########
   9 ->  184  ##################
  10 ->  184  ##################
  ...

import sys
from collections.abc import Mapping, Iterable

def get_total_size(obj, seen=None):
    """递归计算对象及其引用的所有对象的总内存大小"""
    if seen is None:
        seen = set()

    obj_id = id(obj)
    if obj_id in seen:
        return 0

    seen.add(obj_id)
    size = sys.getsizeof(obj)

    # 字符串和字节类型不再递归
    if isinstance(obj, (str, bytes, bytearray)):
        return size

    # 字典类型
    if isinstance(obj, Mapping):
        size += sum(get_total_size(k, seen) + get_total_size(v, seen)
                    for k, v in obj.items())
    # 可迭代类型（排除字符串）
    elif isinstance(obj, Iterable) and not isinstance(obj, (str, bytes)):
        size += sum(get_total_size(item, seen) for item in obj)

    return size

# 对比浅层和深层内存占用
data = {
    "name": "张三",
    "scores": [85, 92, 78, 95, 88],
    "info": {"age": 25, "city": "北京"}
}

shallow = sys.getsizeof(data)
deep = get_total_size(data)

print(f"浅层内存占用: {shallow} 字节")
print(f"深层内存占用: {deep} 字节")
print(f"差异: {deep - shallow} 字节 (被引用对象)")

浅层内存占用: 184 字节
深层内存占用: 856 字节
差异: 672 字节 (被引用对象)