Python 通过不同路径导入相同对象 类属性和基元之间的不同行为

Python3.10.6

假设您有以下文件:

main.py
setter.py
Folder/shared.py

这些内容包括:

# Folder/shared.py
class Shared:
    i = 0 # something that is used in multiple locations

# setter.py
from Folder.shared import Shared
def set_i():
    global Shared
    print("mem in setter: " + hex(id(Shared.i)))
    Shared.i = 2 # set the shared resource

# main.py
IMPORT_VIA_PATH = False
if IMPORT_VIA_PATH:
    import sys, os
    pwd = os.path.dirname(os.path.abspath(__file__))
    shared_path = pwd + '/Folder'
    sys.path.insert(0, shared_path)
    from shared import Shared
else:
    from Folder.shared import Shared
from setter import set_i
set_i()
print(Shared.i)
print("mem in main: " + hex(id(Shared.i)))

If IMPORT_VIA_PATH is False, main prints 2 for i's value, and the memory addresses are different.
If IMPORT_VIA_PATH is True, main prints 0 for i's value, and the memory addresses are the same.

更令人困惑的是，如果在整个过程中，只有i人取代了Shared.i人:

# Folder/shared.py
i = 0 # something that is used in multiple locations

# setter.py
from Folder.shared import i
def set_i():
    global i
    print("mem in setter: " + hex(id(i)))
    i = 2 # set the shared resource

# main.py
IMPORT_VIA_PATH = True
if IMPORT_VIA_PATH:
    import sys, os
    pwd = os.path.dirname(os.path.abspath(__file__))
    shared_path = pwd + '/Folder'
    sys.path.insert(0, shared_path)
    from shared import i
else:
    from Folder.shared import i
from setter import set_i
set_i()
print(i)
print("mem in main: " + hex(id(i)))

则对于IMPORT_VIA_PATH、True或False两者，i保持零，并且存储器地址是the same.这里发生什么事情？