Lookup tables are used when working with Revit MEP components to define parameter values in an external CSV file. This lets you specify multiple part sizes that are based on a table without creating a separate family type for each size. Revit provides a text_file_lookup function that can be used to read the necessary values from a comma-separated values (CSV) file. The location of Lookup Table files is defined by the LookupTableLocation parameter in the Revit.ini file. Folders are created for each type of content installed, such as pipe, conduit, and so on.
Community Video: Correct Pipe Fitting Sizes
Lookup Tables are used in conjunction with type catalogs. For information about creating type catalogs, see The Families Guide.
The syntax for the text_file_lookup function uses the following format:
result=text_file_lookup(LookupTableName, LookupColumn, DefaultIfNotFound, LookupValue)
| Where: | Is: |
| result | the returned value. |
| LookupTableName | the name of the CSV file to lookup. |
| LookupColumn | the name of the column from which the result value is to be returned. |
| DefaultIfNotFound | the value that will be returned if LookupValue is not found. |
| LookupValue | the value to find in the first column of the table. |