How to filter not null data from list of dictionary ?

Question

Hi Team, 
 I need help. 
 I have a list of dictionary like 
 { 
 {name: "Aish", category: "A"} 
 {name: "Jenny", category: "A"} 
 {name: "", category: "C"} 
 {name: "", category: "E"} 
 {name: "", category: "E"} 
 } 
 
 Now I want to filter out only that/those dictionary which has name value not null. 
 Like I want values to return only with name filled, empty rows I don't want. 
 In the example above it should return only first 2 rows as the name is filled there. 
 can you suggest anything?

Stewart Burchell · Accepted Answer

Typically you'd conduct a 2-stage process in your expression: 
 
 loop through each of the items in your array, examine each and where the 'name' is null, return null, other wise return the whole item. You can do this using a!forEach() 
 on the result from 1. use fn!reject() to remove all of the values that are now null 
 
 Here's the full code: 
 a!localVariables(
 local!myArray: {
 { name: "Aish", category: "A" },
 { name: "Jenny", category: "A" },
 { name: "", category: "C" },
 { name: "", category: "E" },
 { name: "", category: "E" }
 },
 fn!reject(
 fn!isnull,
 a!forEach(
 items: local!myArray,
 expression: if(fv!item.name = "", null, fv!item)
 )
 )
) 
 ...and the result is:

Mike Schmitt · Answer

Since I loathe the the old looping functions with a fiery passion these days, I would recommend just utilizing a!forEach() for the heavy lifting here. The trick is, have it return an empty set instead of NULL, which in normal circumstances will not be returned as a member of the resulting array. The one corner case is, for some quirky reason if all items are filtered out, then the result ends up returning a list of empty sets equal in length to the original list, but a!flatten takes care of this handily. 
 a!localVariables(
 local!myArray: {
 { name: "Aish", category: "A" },
 { name: "Jenny", category: "A" },
 { name: "", category: "C" },
 { name: "", category: "E" },
 { name: "", category: "E" }
 },
 
 a!flatten( 
 /* (a!flatten only becomes necessary when the filter would
 cause zero results to be returned) */
 a!forEach(
 items: local!myArray,
 expression: if(
 isnull(fv!item.name),
 {},
 fv!item
 )
 )
 )
 
 /*fn!reject(*/
 /*fn!isnull,*/
 /*a!forEach(*/
 /*items: local!myArray,*/
 /*expression: if(fv!item.name = "", null, fv!item)*/
 /*)*/
 /*)*/
)

How to filter not null data from list of dictionary ?

Top Replies