Calculate Field using variable in arcpy

Question

I've got a problem with my script and hope that someone can help me.

What I ́d like to do is using the field calculator to calculate values for a field using values from another field and a variable in the expression. The script should be as follows:

var_a = 6.2
arcpy.CalculateField_management (in_table, in_field,"[FIELD_A]*100/var_a")

[FIELD_A] contains the values of another field in the same table.

I only know how to integrate var_a in the expression using

arcpy.CalculateField_management (in_table, in_field, "'"+str(var_a)+"'", "PYTHON")

but then I can ́t use the other values for the calculation.

• artwork21: var_a is being seen as just as characters, use either the .format() string method to reference the variable in the expression or use AddFieldDelimiters to help format the expression (pro.arcgis.com/en/pro-app/arcpy/functions/…).

Answer 1

Try passing your variable to your string:

var_a = 6.2
arcpy.CalculateField_management (in_table, in_field,"[FIELD_A]*100/{}".format(var_a))