How to use python to calculate some fields value?

fenggao1

Now, i have a question about how to use python to calculate some fields value.Like fieldname1??fieldname2??fieldname3.When i got that value,how can i make fieldname4 = fieldname1??fieldname2??fieldname3??Thank you.

DanPatterson_Retired

Use the field calculator and set the parser to Python, then click on each field's name with * in between in order get the calculation you need