10 Essential Code Block Techniques for Dynamo

automation dynamo revit May 25, 2024

Are you ready to supercharge your Dynamo workflows? Code blocks are a powerful tool that can streamline your processes and make your scripts more efficient. In this post, we'll explore ten essential techniques for using code blocks in Dynamo. Watch the video below to see these techniques in action, then dive into the detailed blog post to master each method.

Code blocks are incredibly flexible and easy to create, making them a favorite tool of mine. In this post, I'll show you ten valuable ways to use code blocks in your Dynamo scripts. Whether you're new to Dynamo or a seasoned pro, these tips will help elevate your Dynamo skills to the next level. Let's dive in!


One of the most common uses of code blocks is to define values within your Dynamo script. Creating a code block is simple: double-click in some white space, and a code block will automatically appear. Alternatively, you can find it in the library under 'Script' and select 'Code Block.' However, double-clicking is the quickest method.

In a code block, you can set up various values, such as numerical values, strings, and Boolean values. For numerical values, enter the number. For strings, enclose the text in quotes. For Boolean values, type true or false. Remember to end each line in the code block with a semicolon. This tells the code block that you're done with the code for that line. Also, the code block color-codes different types of values: numerical values in blue, strings in orange, and Boolean values in yellow. This makes it easy to distinguish between them at a glance.


Code blocks are also perfect for performing mathematical operations. Instead of using multiple math nodes from the library, you can do everything within a single code block. For example, you can perform simple arithmetic like 10 + 10 and more complex calculations that follow the order of operations, such as (5 + 5) * 10.

Additionally, you can use built-in math functions directly in code blocks. For example, you can use Math.Sqrt to calculate the square root or Math.PI to get the value of pi. Dynamo's Design Script notation makes finding many of these functions easy, as many node names use the same notation. For example, you can use Math.Abs to get the absolute value of a number. This consistency between node names and design script notation is a huge time-saver.


In code blocks, you can define input variables that can be dynamically used within your script. This makes your code blocks more flexible and reusable. Type some text in the code block without quotes to create an input. The code block will interpret this as an input. For example, if you type first + second / third, first, second, and third will be recognized as inputs. You can connect other nodes to these inputs, making the code block adaptable to different values.

This technique is not limited to numerical values; you can use it with strings. For instance, you can concatenate text by joining strings within a code block. This flexibility allows you to create more complex and dynamic scripts without cluttering your workspace with multiple nodes.


Like programming languages, you can declare and use variables in code blocks. This helps organize your script and makes it more readable and maintainable. For example, you can declare variables like first = 10 and second = 20. Once defined, these variables can be used in calculations, such as first + second.

You can also mix and match hard-coded values with inputs. For example, you can define a variable as an input and use it alongside other variables within your code block. This approach provides much flexibility and allows you to create more complex and dynamic scripts.


Code blocks allow you to include if-else statements, enabling your scripts to make decisions based on specific conditions. This is crucial for creating dynamic and responsive workflows. For example, you can write an if-else statement to check if one variable is greater than another and output different values based on the result.

Conditional logic in code blocks can be used to compare numerical values, strings, or even complex objects. This makes it a powerful tool for creating scripts that need to adapt to different conditions and inputs.


You can generate sequences of numbers using ranges, which helps when creating grids, parametric arrays, and other tasks that require a series of values. The syntax for creating ranges in code blocks is straightforward. For example, you can type 0..10 to create a range from 0 to 10. You can also specify a step value, such as 0..100..5, which creates a range from 0 to 100 in increments of 5.

This technique is not limited to numerical values; you can also create ranges of letters. For example, "A".."Z" generates the entire alphabet. You can make more complex patterns and sequences by specifying a step value.


Like with ranges, you can define complex number and letter sequences using code blocks. The syntax is similar to ranges, but you use the pound sign ( # ) to specify the number of elements or divisions. For example, 0..#20..5 creates a sequence starting at 0 with 20 elements, incrementing by 5.

This technique is also applicable to letters. For example, "A"..#5..2 creates a sequence starting at 'A' with 5 elements, incrementing by 2 letters. This flexibility allows you to make precise and customized sequences within your scripts.


Lists in Dynamo are fundamental for managing collections of data. Code blocks allow you to create and manipulate lists efficiently. To create a list in a code block, use square brackets to enclose the elements and separate them with commas. For example, list1 = ["A","E","F"] creates a list of strings, while list2 = [22, 45, 78] creates a list of numbers.

You can also perform operations on lists, such as accessing specific elements or counting the number of items. For example, list1[2] returns the third element of the list (remember, lists are zero-indexed), and List.Count(list2) returns the number of items in list2.


You can use code blocks to generate geometric elements in Dynamo, rather than using nodes. For example, you can create a point using the Point.ByCoordinates function and then create a line using the Line.ByStartPointEndPoint function. By combining these functions, you can build complex geometries step by step.

You can also use variables to condense multiple steps into a single code block. This approach makes your script more compact and easier to manage, especially when dealing with complex geometries.


Taking it a step further, you can use code blocks to script the creation of Revit elements; for example, you can use Revit.Wall.ByCurveAndHeight function to create walls. This requires some inputs, such as the curve defining the wall's path, the wall's height, and the wall's base level.

By combining code blocks with Revit-specific functions, you can automate the creation of Revit elements and streamline your scripts.



Code blocks can significantly enhance your productivity, making your scripts more flexible, efficient, and easier to manage. From defining values and performing calculations to creating geometry and Revit elements, code blocks provide Dynamo users with a powerful and flexible toolset. 

One word of caution: Try to keep your code blocks relatively simple. I've seen scripts containing code blocks that were forty to fifty lines long. This was WAY too much code in a single block, making troubleshooting the script very difficult. I keep my code blocks to five lines or fewer. Use multiple code blocks if necessary. 

Try these techniques in your next Dynamo project and see the difference they make! For more tips and tutorials, check out my other blog posts and subscribe to my newsletter.

Join ArchSmarter!

Sign up for ArchSmarter updates and get access to the ArchSmarter Toolbox, a collection of time-saving Revit macros, Dynamo scripts, and other resources. Plus you'll get weekly productivity tips, webinar invitations and more! Don't worry, your information will not be shared.

We hate SPAM. We will never sell your information, for any reason.