python - Python 的 .remove() 方法删除列表中的意外项

Question

我写了这个脚本：

soilMod = ['ptaaco']
n = 2

soilModSplit = [soilMod[i:i+n] for i in range(0, len(soilMod), n)] # This returns ['pt', 'aa', 'co']

alphaTest = soilModSplit # I want to maintain the original list built before I remove items below. This returns ['pt', 'aa', 'co'] as well

if 'pt' in soilModSplit:
      soilModSplit.remove('pt')
      print soilModList # This returns ['aa', 'co']
      print alphaTest # This also returns ['aa', 'co'] It's missing the original ['pt', 'aa', 'co'] and I didn't ask the script to remove it from this particular list.

出于某种原因，当我从 soilModSplit 中删除项目 ('pt') 时，它也会从 alphaTest 中删除该项目。这是预期的结果吗？似乎建立在 soilModSplit 上的任何变量（在本例中为 alphaTest）都依赖于对 soilModSplit 采取的任何操作。也许我做错了什么？有没有办法解决这个问题？

谢谢，迈克

Answer 1

alphaTest = soilModSplit 

alphatest只是绑定到的同一个列表的另一个名称soilModSplit。做一个浅拷贝：

alphaTest = list(soilModSplit )

Answer 2

当您这样做时alphaTest = soilModSplit，您不会创建副本。您只有两个名称引用同一个列表。如果要保存副本，请执行alphaTest = list(soilModSplit).