Python exec() command

1

following problem:
i have a string i want to execute like:

string = “2*A+B”
usually it should work like result = exec string.
when i try that in dynamo i receive only error messages.

any clue?

2

Please show a screenshot…

Generally you cannot perform math on strings… (Neither in Python nor in Dynamo)

3

Posting the error and the code would definitely help. Exec should work fine inside of Dynamo:

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You’re possibly trying to reference an argument before assigning it. Maybe having keyword arguments would be easier in that case?

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4

But using strings will give wrong results, at least that’s was what I meant in my original reply :wink:
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Alternatively you can import the “math” module in Python
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5

dimitar thank you for your reply.
just found out that it is a problem with dynamo 2+
going back to 1.3 everything is working.
btw code is just the same as your smple :wink:
tx peter

6

dimitar, asfaik math is not capable of calculating strings… true?

7

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weird thing it that dynamo doe not calculate but writes output multiple times

8

It seems that it is repeated the number of times that your formula states?
E.g. “NAF*2” is repeated twice…

Can you show your entire script and possibly the input from Dynamo if you have that? It would make it easier to understand… :slight_smile:

9

Exactly that is the Point ?!

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10

If any of your input arguments are strings and you want to use math on them, you’ll first have to convert them to a numeric object. For example:

A = float(“1.23”)
B = float(“4.56”)

11

dimitar thank you.
thought that even variables shall be string.
by converting them to numbers solved the problem