This page shows how to use the Python SDK to render a visualization from the chart specifications that are provided within a Conversational Analytics API response. The sample code extracts the chart specification (in the Vega-Lite format) from the response's chart
field and uses the Vega-Altair library to render the chart, save it as an image, and display it.
Example: Render a bar chart from an API
This example shows how to render a bar chart from a Conversational Analytics API agent response. The example sends a request with the following prompt:
"Create a bar graph that shows the top five states by the total number of airports."
The sample code defines the following helper functions:
render_chart_response
: Extracts the Vega-Lite configuration from thechart
message, converts it to a format that can be used by the Vega-Altair library, renders the chart, saves it tochart.png
, and displays it.chat
: Sends a request to the Conversational Analytics API using theinline_context
variable and the currentmessages
list, processes the streaming response, and if a chart is returned, callsrender_chart_response
to display it.
To use the following sample code, replace the following:
- sqlgen-testing: The ID of your billing project that has the required APIs enabled.
- Create a bar graph that shows the top five states by the total number of airports: The prompt that you want to send to the Conversational Analytics API.
from google.cloud import geminidataanalytics
from google.protobuf.json_format import MessageToDict
import altair as alt
import proto
# Helper function for rendering chart response
def render_chart_response(resp):
def _convert(v):
if isinstance(v, proto.marshal.collections.maps.MapComposite):
return {k: _convert(v) for k, v in v.items()}
elif isinstance(v, proto.marshal.collections.RepeatedComposite):
return [_convert(el) for el in v]
elif isinstance(v, (int, float, str, bool)):
return v
else:
return MessageToDict(v)
vega_config = _convert(resp.result.vega_config)
chart = alt.Chart.from_dict(vega_config)
chart.save('chart.png')
chart.display()
# Helper function for calling the API
def chat(q: str):
billing_project = "sqlgen-testing"
input_message = geminidataanalytics.Message(
user_message=geminidataanalytics.UserMessage(text=q)
)
client = geminidataanalytics.DataChatServiceClient()
request = geminidataanalytics.ChatRequest(
inline_context=inline_context,
parent=f"projects/{billing_project}/locations/global",
messages=messages,
)
# Make the request
stream = client.chat(request=request)
for reply in stream:
if "chart" in reply.system_message:
# ChartMessage includes `query` for generating a chart and `result` with the generated chart.
if "result" in reply.system_message.chart:
render_chart_response(reply.system_message.chart)
# Send the prompt to make a bar graph
chat("Create a bar graph that shows the top five states by the total number of airports.")