How to infere data with Python based node

Hi all!
I would ask you a support to identify errors in a IronPython based node for if-elif-else statement.

I have breakdown of Dynamo when running the pipeline I tried to develop.

This Python node should have as Input n lists of n items that are parameters and values inserted, and get, in the BIM model. It works when I use one input, but not the lists. I admit I am not great enough to write a Python script, so I think it is a very stupid error I do (even if the visual studion Validation does not give me any alert.

The code I write is:

s=IN[0]
l=IN[1]
n=IN[2]
g=IN[3]
r=IN[4]
t=IN[5]
f=IN[6]

if (s == "≤1/8" and l == "assenti" and n == "≤1/5 ≤50 mm" and g == "≤2/5" and r == "≤1/14 (7%)" and t == "≤1/10 (10%)" and f == "ammissibili, purchè non passanti"):
	c="1"
elif (s == "≤1/5" and l == "assenti" and n == "≤1/3 ≤70 mm" and g == "≤2/3" and r == "≤1/8 (12%)" and t == "≤1/5 (20%)" and f == "ammissibili, purchè non passanti"):
	c="2"
else:
	c="3"
# Assegnare l'output dell'utente alla variabile OUT.
OUT = c

Here, the input are 6, but can be more, according to the number of elements I go to select in the model (it can vary case by case), so this is another question to be inserted as input definition. The output should be a list itself in a number equal to the number of elements selected in the BIM model.

Can you help me?

I will be very glad

Bests

Silvana

This is because you aren’t iterating over the list of inputs, but instead working with each list as a number. You need to wrap the entire statement in a for loop, or utilize list comprehension to do so.

However because you indicated you have an N dimensional list, that it ‘it could be a list of values, or a list of lists of values, or a list of lists of lists of values’, you may find it easier to wrap the python on a custom node to facilitate the unknown structure of data and enable list at level and lacing per standard Dynamo.

Thank you @JacobSmall,
I am going to try to use the custom node (a new diyf file), instead of using a Python Script node.

I was studying the for loop (but with no real awareness about the pros), but I do not how to utilize the list comprehension.

I am going to deep these concepts and try!

Thank you very much!

1 Like
s=IN[0]
l=IN[1]
n=IN[2]
g=IN[3]
r=IN[4]
t=IN[5]
f=IN[6]

c = []

def method_name():
    for item in lst(s,l,n,g,r,t,f):
     if (s == "≤1/8" and l == "assenti" and n == "≤1/5 ≤50 mm" and g == "≤2/5" and r == "≤1/14 (7%)" and t == "≤1/10 (10%)" and f == "ammissibili, purchè non passanti"):
        c="1"
     elif (s == "≤1/5" and l == "assenti" and n == "≤1/3 ≤70 mm" and g == "≤2/3" and r == "≤1/8 (12%)" and t == "≤1/5 (20%)" and f == "ammissibili, purchè non passanti"):
        c="2"
     else:
        	c="3"
     return c, item

def method_name():
    c, item = method_name()
    return c, item

c, item = method_name()

I have the same breakdown (dynamo and Revit close)

Are your variable lists of a matching structure and depth? Ie: do you have 3 items in each list? Or could s have 5 items and n have 2?

each list has the same number of items (equal to the number of selected elements)

Hello @fyffe
a trick using a dictionary and list comparison to avoid multiple and operator

import sys
def getKeybyValue(mydict, searchlst, default):
	for key, valuelst in mydict.items():
		if list(valuelst) == list(searchlst):
			return key
	return default		

dataEnteringNode = IN
#transpose if list contain sublist
if all([isinstance(i, list) for i in dataEnteringNode]):
	dataEnteringNode = [i for i in zip(*dataEnteringNode)]
else:
	dataEnteringNode = [dataEnteringNode]

mydict = {
"1": ["≤1/8","assenti", "≤1/5 ≤50 mm", "≤2/5", "≤1/14 (7%)", "≤1/10 (10%)" , "ammissibili, purchè non passanti"] ,
"2": ["≤1/5", "assenti", "≤1/3 ≤70 mm", "≤2/3", "≤1/8 (12%)",  "≤1/5 (20%)",  "ammissibili, purchè non passanti"] 
}
out = []
for sublist in dataEnteringNode:
	i = getKeybyValue(mydict, sublist, default = "3")
	out.append(i)
	
OUT = out

Note: when you post some code please use image button after selection of your code

2 Likes

i would use a loop and a zip method here. but to catch missing or uneven elements from list you can use zip_longest() from itertools.