How can I keep the first two elements from CSV values in a string

I have a Table where one of the columns contains text elements separated by commas. I want to keep the first element (if there is only one) or the first two (if the are more than one). There also could be empty lines. For example, from:

abcd, efgh, tyui

[]

lkjh, poiu

wert

I want to get

abcd, efgh

[]

lkjh, pou

wert

I know how to do this with a for loop. But the idea would be to use regular expressions or something similar to accelerate the process. The Table has almost 2M elements.

Any suggestion would be of great help. Thanks.

Answer 1

[Stephen23]

S = ["";"philosopher,historian,writer,political activist,literary critic";"philosopher";"philosopher,writer"]

S = 4x1 string array
    ""
    "philosopher,historian,writer,political activist,literary critic"
    "philosopher"
    "philosopher,writer"

T = regexp(S,'^[^,]*(,[^,]+)?','match','once','emptymatch')

T = 4x1 string array
    ""
    "philosopher,historian"
    "philosopher"
    "philosopher,writer"

[Gustavo Schwartz]

Thanks Stephen23! This is exactly what I needed.

Answer 2

[Walter Roberson]

FilteredData = regexp(YourTable.ColumnName, '^[^,]+(,\s+[^,]+)?', 'match', 'once');

[Gustavo Schwartz]

Thanks, Walter, for your soon response. This regexp works to extract the words before the first comma, but I need to extract the words before the second comma (if there are more than one). Suppose I have:

"philosopher,historian,writer,political activist,literary critic"

"philosopher"

"philosopher,writer"

I want to get

"philosopher,historian"

"philosopher"

"philosopher,writer"

I would appreciate if you can provide a regexp to solve this problem.

[Gustavo Schwartz]

Aparently, this regexp works:

regexp(Table.Colum, '^[^,]*(?:,[^,]*)?','match')