# Working with Dictionaries in Python
**URL:** https://forum.dynamobim.com/t/working-with-dictionaries-in-python/43440
**Category:** Revit
**Tags:** python
**Created:** [November 21, 2019, 10:08am UTC](https://forum.dynamobim.com/t/working-with-dictionaries-in-python/43440 "2019-11-21T10:08:39Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@bialmeida](https://forum.dynamobim.com/u/bialmeida)
#### Post date: [November 21, 2019, 10:08am UTC](https://forum.dynamobim.com/t/working-with-dictionaries-in-python/43440/1 "2019-11-21T10:08:39Z")
Hey everyone,
i created a python node and need some help finding a way of getting what i want, i am not very familiar with dictionaries yet:
I would like python to check if the keys are identical and in this case calculate the areas of the rooms contained in Dictionary 1, copy this value into a Parameter of the fist area (index 0) in Dictionary 2, for example:
if key Dictionary 1 == key Dictionary 2, then calculate area Room 1931747 + Area Room 1931748 + Area Room 1931749. Then pick index 0 of corresponding list in Dictionary 2 (Area 1931821) and copy this value into a Project Parameter called room area. The other Areas contained in the same list should get 0 as value.
I am doing this because i want to create a schedule that Shows Rooms and Areas at the same time in Revit, so i need to get the area of all Rooms into the gross area schedule… Thanks!!
---
### Author:  [@Kibar](https://forum.dynamobim.com/u/Kibar)
#### Post date: [November 21, 2019, 9:26pm UTC](https://forum.dynamobim.com/t/working-with-dictionaries-in-python/43440/2 "2019-11-21T21:26:49Z")
I guess there might be an easier way to reach your goal (using less python), but this seems like a great python learning task 🙂
It might cause confusion because you´ll have to translate between Python dictionaries and .NET dictionaries.
To break down what you´ll need to know:
- [Dictionaries in Python and how to loop through them.](https://realpython.com/iterate-through-dictionary-python/)
- [Convert between units (RevitAPI)](https://www.revitapidocs.com/2020/9cc2c0ea-f59f-9d76-ce19-ae7eede03bbd.htm)
- get/set parameter value in python (search this forum)
- [Create/Output Dynamo dictionaries](https://digitteck.com/dotnet/dynamobimdotnet/dictionaries-from-python-to-graph/) (in case you want to output a new dictionary)
* * *
Take apart your dictionaries before feeding it into the python script (to keep it easier):
Try to break down your tasks into small pieces and go from there.
Everything that I have commented out has been answered in one way or another on this forum.
```
# Recreate python dictinairy
room_keys = IN[0]
room_values = UnwrapElement(IN[1])
room_dict = dict()
for key, value in zip(room_keys,room_values):
room_dict[key]= value
# Recreate python dictionairy
area_keys = IN[2]
area_values = UnwrapElement(IN[3])
area_dict = dict()
for key, value in zip(area_keys, area_values):
area_dict[key]= value
for level in room_dict.keys():
if level in area_dict.keys():
# Get all rooms of that level (rooms_of_level)
# Create total value 'total = 0.0'
# for room in rooms_of_level:
# -> Get room area (sqf)
# -> total += room area
# Convert internal units of total area
# sqf to m2 (RevitAPI)
# Get Areas on that level
# for index, area in enumerate(Areas):
# -> Get parameter 'room area' of area
# -> if index == 0:
# -> Set parameter 'room area' = total_sqm
# -> else:
# -> Set parameter 'room area' = 0.0
```
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### Author:  [@cgartland](https://forum.dynamobim.com/u/cgartland)
#### Post date: [November 21, 2019, 11:14pm UTC](https://forum.dynamobim.com/t/working-with-dictionaries-in-python/43440/3 "2019-11-21T23:14:53Z")
This can also be simplified slightly by directly constructing a dictionary with the tuples output by the zip function:
`room_dict = dict(zip(room_keys, room_values))`
Also, .NET dictionaries are automatically converted in Dynamo Core 2.1 and newer, but I don’t think this has been implemented in the Dynamo Revit versions yet.
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### Author:  [@bialmeida](https://forum.dynamobim.com/u/bialmeida)
#### Post date: [November 25, 2019, 8:58am UTC](https://forum.dynamobim.com/t/working-with-dictionaries-in-python/43440/4 "2019-11-25T08:58:19Z")
Thank you very much, this is a gret challenge for me!
I would have a first question if you dont mind:
python dictionaries work with pairs, right (key + value)?
I can’t understand how a dictionary can be created once i provide a different number of keys (levels?) and values (areas?)…How does the Dictionary look like in the end? How are the pairs created?
Thanks!
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### Author:  [@Kibar](https://forum.dynamobim.com/u/Kibar)
#### Post date: [November 25, 2019, 9:16am UTC](https://forum.dynamobim.com/t/working-with-dictionaries-in-python/43440/5 "2019-11-25T09:16:07Z")
{ key : value }
In this case your key is the level name and its value a list of areas.
{ string : list }
{ “Obergeschoss” : [area1, area2]}
You can add new elements to this list.
---
### Author:  [@neel-studio4](https://forum.dynamobim.com/u/neel-studio4)
#### Post date: [January 12, 2021, 7:13am UTC](https://forum.dynamobim.com/t/working-with-dictionaries-in-python/43440/6 "2021-01-12T07:13:47Z")
just as an added help ,
to write or edit dictionaries in dynamo python u need to add the following imports
```
> import sys
> import clr
> import System.Collections.Generic
> Dictionary = System.Collections.Generic.Dictionary[System.String,System.Object]()
>
> # The inputs to this node will be stored as a list in the IN variables.
> dict = IN[0]
>
> # Place your code below this line
>
> # Assign your output to the OUT variable.
> OUT = dict
```
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### Author:  [@c.poupin](https://forum.dynamobim.com/u/c.poupin)
#### Post date: [January 12, 2021, 11:44am UTC](https://forum.dynamobim.com/t/working-with-dictionaries-in-python/43440/7 "2021-01-12T11:44:46Z")
Hello,
since Dynamo 2.3 the Dynamo wrapper convert automatically a Python dictionary to a Net dictionary
Before this version (like version 2.0.4) it is advisable to convert a Python dictionary to Net only if the dictionary is assigned to the variable OUT (and the key must be a string).
Inside the node we can write and edit a Python dictionary without problems
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### Author:  [@c.poupin](https://forum.dynamobim.com/u/c.poupin)
#### Post date: [November 22, 2022, 4:00pm UTC](https://forum.dynamobim.com/t/working-with-dictionaries-in-python/43440/8 "2022-11-22T16:00:09Z")
A post was split to a new topic: [Python Dictonnary with Sheets List](https://forum.dynamobim.com/t/python-dictonnary-with-sheets-list/83380)