Format String Node

The Format String node inserts values into a string using either a Python compatible string format syntax or Blender’s format specifier syntax.

This node simplifies string construction, allowing values to be combined and formatted without converting numbers to strings or using multiple concatenate nodes.

See also

Python Syntax references: - Python Format String Syntax - {fmt} Format String Syntax

Inputs

Format

A string using either python format style or Blender’s format specifier. For example, Count: {} inserts the first input value in place of the {}.

Additional input values (Float, Integer, or String) can be managed in the Format Items list in the sidebar.

Properties

Format Items

A list view. to manage the dynamic list of inputs used in the format string. Each entry corresponds to a value that can be inserted into the format using a placeholder. See Input Naming Behavior to understand how inputs must be named.

Socket Type

The type of value for this input:

Float:

A floating-point number (e.g. 3.14).

Integer:

An integer number (e.g. 42).

String:

A text string.

Outputs

String

The formatted string.

Notes

• Supports both unnamed ({}) and named ({name}) placeholders. However, all unnamed placeholders must appear before any named ones.

• Only float, integer, and string inputs are supported.

• Python-style conversions such as !r are not supported.

• Sub-attribute access (e.g. {vector.x}) is not supported.

• Percent-based formatting (e.g. %d, %s) is not supported.

• Alternate form specifiers using # (e.g. {:#x}) are not supported.

• Locale-based formatting using L (as in the fmt library) is not supported.

• Grouping options like thousands separators (e.g. {:,} or {:_}) are not supported.

Input Naming Behavior

Each input must have a unique, valid identifier name used in placeholders (e.g. {value}). This node uses special logic to automatically assign names to new inputs:

• If connected, the first character of the linked socket’s name is used.

• Otherwise, names default to letters a through z.

• If needed, the original socket name is converted to a valid identifier.

• If all else fails, a unique suffix is appended (e.g. _001, _002).

Important

Input names must be valid identifiers and must be unique. If a name is invalid, the format operation may fail or produce incorrect output.

Examples

Basic

• Format: Count: {}

• Inputs: Integer with value 5

• Result: Count: 5

Multiple Values

• Format: X: {}, Y: {}

• Inputs: Float 1.5, Float 2.0

• Result: X: 1.5, Y: 2.0

Named Inputs

• Format: Size: {width} x {height}

• Inputs: width=1920, height=1080

• Result: Size: 1920 x 1080

Padded Numbers

• Format: Frame_{:04}

• Inputs: Integer 12

• Result: Frame_0012

Number Format (Template Style)

• Format: ##.00

• Input: Float 3.1415

• Result: 03.14

Path with Frame Number

• Format: /output/image_{:04}.png

• Input: Integer 42

• Result: /output/image_0042.png