How to add values to an already existing key in dictionary

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#1

Hi!
I’m trying to add new values to an already existing key in my dictionary.
Let’s suppose I have the following dictionary:

my_dict {
‘key_1’: ‘value_1’,
‘key_2’: ‘value_2’
}

My goal, in this example, is to add the values on this list: [‘value_3’, ‘value_4’] either to key_1 or to key_2.
More explicitly, I intend to get a new dictionary as showed below:

my_dict_2 {
‘key_1’: [‘value_1’, ‘value_3’, ‘value_4’],
‘key_2’: ‘value_2’
}

I’ve read about some approaches that suggest to replace ‘value_1’ with a new string comprised of the old value and all of the new ones with an assign activity:

my_dict(“key_1”) = my_dict(“key_1”)+", "+ “value_3”+…

Which, in turn, returns this:

my_dict_3 {
‘key_1’: ‘value_1, value_3, value_4’,
‘key_2’: ‘value_2’
}
Unfortunately this doesn’t work for me.

Does anyone know a workaround?
Thank you!

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#2

Hi @franrua02 ,

Correct only can u share your workflow or picture

Regards,
Arivu

#3

dictionary

Name of dictionary: out_DiccArchivosDefectuosos
1 activity: I check if key ‘Archivo’ already exists in dictionary.
2 activity:
If it does (Then):
I proceed as showed above: Replace existing value with new string.
If it does not (Else):
I create it and add first value.

The activities above are inside of a For Each activity: I’m iterating over some files.

I hope this is clear enough!

#4

@franrua02 you are going correct.
Can you share the dictionary datatype and the output/error you are getting?

#5

Hi @franrua02,

  1. In that case I suggest you define all your values as a List. This is because List type will let you add items to it independent of which key you want to update.
    dict {
   ‘key_1’: {‘value_1’},
   ‘key_2’: {‘value_2’ ‘value_3},
    }

where {‘value_1’} and {‘value_2’ ‘value_3} are type List.

  1. To do this you can first initialize three variables

    image
    image914×117 10 KB

  2. Then you can in a for loop add any number of values to the list. In this example, I have used two hardcoded lists, you can generalize the approach in a for loop such that each time you run the loop a new list is initialized and the string items are populated to it accordingly.

    image
    image1306×264 12.9 KB

  3. Once you know all your strings are in the above list / lists, you are ready to add it to the dictionary variable using Add to collection activity

    image
    image1349×428 21.1 KB

  4. Finally, if you want to check your dictionary has updated values you can use
    image

  5. Your output will look like this for index 0
    image

Here is the workflow you can refer: AddListToDictValue.xaml (12.6 KB)

Improvements: If you can find an elegant way to directly add Keys(String), Values(List(ofString)) to the DictExample, you could use Add To Collection activity too.
In my example, I have used the key to assign values in Step 4.

Hope this helps!

#6

The same request was solved here: https://forum.uipath.com/t/filter-dictionary-values-dynamically-and-get-keys-of-matches

:slight_smile:

#7

dict
I’m not getting any error. I just want my dict to have the structure shown in my_dict _2 (see above) instead of that of my_dict _3, which is what I’m getting.

#8

Hey, Jeevith. Wow, thorough answer. This could work, I’ll try it! Thank you!
Although I was kinda hoping to get it done with a one line code like in Python with the append method. :sob: :sob:

#9

@franrua02,

I .append() to your thought process, as I come from the python world as well!

When I started with UiPath I felt the same: Why do we have to be so aware of initializing variables? Why make things so complicated?

But trust me when I tell you this. .Net grows on you quite quickly, not because the methods are easy or the documentation from Microsoft is a boon, but because these methods you learn via UiPath can easily be extended to either C# or PowerShell. Most often you will end up needing one of these in a large automation project. The dots will then connect :slight_smile:

Do try the solution out, and if you have any questions or improvements do share them in this threat. I would like to learn from them as well :slight_smile:
Cheers!