adding a blank column using ironpython

[Sundaram Sridharan]

I need to check if a column is present (which came in through a pivot operation) and if not I need to add it to the table with blank values for all rows. I am looking for syntax of table.AddColumns for this (what is datasource here).

Also can this be only triggered by an action item in text area Ideally I would like to add this as a transform right after pivot in data canvas.

[Gaia Paolini]

Try this (replace column names and data types as required): check the indentation (got mixed up when pasting)

 

from Spotfire.Dxp.Data import *

desiredColsDict =

{'mydatecol':DataType.Date,'myintegercol':DataType.Integer,'mystringcol':DataType.String}

for key,value in desiredColsDict.items():

try:

expression = str(value)+'(NULL)'

dataTable.Columns.AddCalculatedColumn(key,expression)

except:

pass

[Gaia Paolini]

forgot to add that dataTable will be the input parameter (of type data table). Instead of using the e.g. DataType.String you could put the actual value (in this case, 'String'). Seems that adding a null column needs a cast to the appropriate data type, otherwise it defaults to Integer.