# Copy dictionary and modify it without affecting the original

**URL:** <https://forum.inductiveautomation.com/t/copy-dictionary-and-modify-it-without-affecting-the-original/62297>\
**Category:** Ignition\
**Tags:** ignition81\
**Created:** [July 26, 2022, 9:12am UTC](https://forum.inductiveautomation.com/t/copy-dictionary-and-modify-it-without-affecting-the-original/62297 "2022-07-26T09:12:13Z")\
**Posts on this page:** 1\
**Showing post:** 9

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**Author:** ![lrose](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/lrose/32/62724_2.png) [@lrose](https://forum.inductiveautomation.com/u/lrose)\
**Post date:** [July 26, 2022, 3:34pm UTC](https://forum.inductiveautomation.com/t/copy-dictionary-and-modify-it-without-affecting-the-original/62297/9 "2022-07-26T15:34:03Z")

</div>

As @bkarabinchak.psi pointed out even though the structure “looks” like a `dict` it isn’t actually a `dict`.  
Actually the type of a perspective property when accessed from a script is:[com.inductiveautomation.perspective.gateway.script.PropertyTreeScriptWrapper.ObjectWrapper](https://files.inductiveautomation.com/sdk/javadoc/ignition81/8.1.1/com/inductiveautomation/perspective/gateway/script/PropertyTreeScriptWrapper.ObjectWrapper.html).

Thus deepcopy chokes when it runs into an object that it doesn’t know how to handle.

If you need a true deepcopy, then you have couple of options.

1. Write a function which recursively loops through the structure and correctly maps objects to dictionaries, and arrays to lists.
2. Encode to JSON and de-encode to guarantee you’re dealing with native Python objects

I have done both of those things in the past.

Note: Option 1 will work for “perspective properties”, it doesn’t account for other possible types that aren’t handled by deepcopy. The assumption I have made here is that if it isn’t an object, or array, then it is a basic type (string,integer,float,etc…). The function can/should be modified to handle other types if you need that particular thing.

Code for option 1:

```python
def recursiveCopy(original):
    from copy import deepcopy
    from com.inductiveautomation.ignition.common.script.abc import AbstractMutableJythonMap,AbstractMutableJythonSequence

    if isinstance(original,AbstractMutableJythonMap):
        return {key:recursiveCopy(value) for key,value in original.iteritems()}

    if isinstance(original,AbstractMutableJythonSequence):
        return [recursiveCopy(item) for item in original]

    return deepcopy(original)

```

Code for Option 2:

```python
from copy import deepcopy
pen = deepcopy(system.util.jsonDecode(system.util.jsonEncode(self.view.custom.penEjemplo)))

```

There are reasons to go with option 1 over option 2, but for what it looks like you’re trying to do either will work.

I will say though, that if I were trying to modify a pen in a power chart, I would just modify the pen, not sure why you need a copy for that.

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