You combine whereClause3 and whereClause4 with the AND operator.
As gm70560 wrote, the variables workforceField, workforceindex are not defined. That's why, first you have to define them. I guess workforceindex is a double or at least a number datatype like farmfieldindex. So you have to Change:
whereClause3 = "\"%s\" = '%s'" % (workforceField, workforceindex)
to:
whereClause3 = "\"%s\" = %s" % (workforceField, workforceindex)
The whereClause4 is not defined (commented out). You have to change
whereClause = "\"%s\" = '%s'" % (farmField, farmfieldindex)
to:
whereClause4 = "\"%s\" = %s" % (farmField, farmfieldindex)
Is that right? (I removed the single quotes for the farmfieldindex)
Another reason for getting an error should be the following:
whereClause3 + "AND" + whereClause4
Is the same like: "\"%s\" = %s" + "AND" + "\"%s\" = %s"
Is the same like: "\"%s\" = %sAND\"%s\" = %s"
Thus, you have no blank between the value (workforceindex) of the first part of the where clause and the AND Operator. Change the Select Layer by Attribute Function to the following and it should work:
arcpy.SelectLayerByAttribute_management(countiesL, "NEW_SELECTION", whereClause3 + " AND " + whereClause4)
If it still not working check the delimiters in the where clause (have a look at the AddFieldDelimiters function)
Best Answer
If you want the user to specify both a distance and units, as can be found in the Buffer tool (and most other tools that specify a distance), you can use the Linear Unit parameter. You can pass this whole parameter value to the tool
The distance passed to buffer can be numeric (in which case it's in the units of the feature class) or as numeric with units (meters, feet, degrees, etc).