import NXOpen

def main():
    theSession  = NXOpen.Session.GetSession()
    workPart = theSession.Parts.Work
    lw = theSession.ListingWindow
    lw.Open()
    
    for sheet1 in workPart.DrawingSheets:
        lw.WriteLine( sheet1.Name )
        lw.WriteLine( sheetSize(sheet1) )

def sheetSize(sheet1):
    size = [1189, 841, 594, 420, 297, 210, 148, 105, 74, 52, 37, 26, 18]

    if sheet1.Height > sheet1.Length:
        return "A" + str( size.index(sheet1.Height) )
    else:
        return "A" + str( size.index(sheet1.Length) )

if __name__ == '__main__':
    main()

Imports System
Imports NXOpen

Module NXJournal
    Sub Main (ByVal args() As String) 
        Dim theSession As Session = Session.GetSession()
        Dim workPart As Part = theSession.Parts.Work

        Dim lw As ListingWindow = theSession.ListingWindow
        lw.Open

    Dim dwgs As Drawings.DrawingSheetCollection = workPart.DrawingSheets
    For Each sheet As Drawings.DrawingSheet In dwgs
            lw.WriteLine( getSize(sheet) )
        Next

    End Sub

    Function getSize(ByVal drawingSheet1 As Drawings.DrawingSheet)
        Dim height As Integer
        Dim length As Integer
        Dim i As Long

        Dim A() As Integer = {1189, 841, 594, 420, 297, 210, 148, 105, 74, 52, 37, 26, 18}

        height = drawingSheet1.Height
        length = drawingSheet1.Length

        For i = 0 to UBOUND(A)
        if A(i) = height then
        if i = 0 then
            getSize = "A" & i
            exit for
        else
            if A(i-1) = length then
            getSize = "A" & (i-1)
            exit for
            elseif A(i+1) = length then
            getSize = "A" & i
            exit for
            end if
        end if
        end if
        Next
    End Function

End Module