Example of updating schema in TFX

[albertnanda]

I have created a schema using SchemaGen. I want to update one of the fields from required to optional. How can I do that?
https://www.tensorflow.org/tfx/tutorials/tfx/components_keras in this tutorial, every field is required. How can I make one of the fields optional.

Another question is how do I access the "domain" information from context.show(schema_gen.outputs['schema'])
programmatically.

[Mikehem]

1. Changing schema feature from optional to required and vice versa

first get the feature from the schema

feature = tfdv.get_feature(schema, feature_name) # this will be the column

for changing from required to optional add a value between 0.0 to 1.0

feature.presence.min_fraction = 0.9

for changing from optional to required

feature.presence.min_fraction = 1.0

display the schema to check if the changes have occured as desired

tfdv.display_schema(schema)

2. Getting the domain values from SchemaGen

This may be a workaround for now. When you run the context, you will get a URI for the run metadata. You can also get it by running this -> schema_gen.outputs['schema'].to_json_dict()['artifacts'][0]['artifact']['uri'] + '/schema.pbtxt'

schema_uri = ''path to tfx pipeline/tfx/pipeline/SchemaGen/schema/19/schema.pbtxt'
schema_1 = tfdv.load_schema_text(schema_uri)
tfdv.get_domain(schema_1, "company")

[rmothukuru]

@albertnanda,
Can you please let us know if @Mikehem's comment worked for you. Thanks!

[albertnanda]

It works, closing this issue