How to pass values into a Multi-Select Pick List

We successfully create EnhancementRequest's through python using the clarizen api.

However, when we try to assign multiple values to a field that is of type: Multi-Select Pick, we get errors.

We can assign a value to that Multi-Select Pick list as long as we just do a single item, but if we try to pass multiple items we get this error:

b'{"errorCode":"General","message":"Can not convert value \'[\\r\\n  \\"Commercial\\",\\r\\n  \\"Residential\\"\\r\\n]\' to type \'MultiPickList\' (Field name: \'C_CustomerType_UPDATED\')","referenceId":"1Yr3BdQJbL9xzmuzNW5O4I"}'

Does the api allow assigning multiple values to the Multi-Select Pick list, of so how?

I have tried it as a tuple:

('Commercial', 'Residential')

a list:

['Commercial', 'Residential']

a string:

'Commercial, Residential'

Again, so far we can only assign a single value to it such as 'Commercial', but not a list of values to the field.