How to construct a "text/csv" payload when invoking a sagemaker endpoint - pandas

Question

My training data looks like
df = pd.DataFrame({'A' : [2, 5], 'B' : [1, 7]})
I have trained a model in AWS Sagemaker and I deployed the model behind an endpoint.
The endpoint accepts the payload as "text/csv".
to invoke the endpoint using boto3 you can do:
import boto3
client = boto3.client('sagemaker-runtime')
response = client.invoke_endpoint(
EndpointName="my-sagemaker-endpoint-name",
Body= my_payload_as_csv,
ContentType = 'text/csv')
How do i construct the payload "my_payload_as_csv" from my Dataframe in order to invoke the Sagemaker Endpoint correctly?

Answer 1

if you start from the dataframe example
df = pd.DataFrame({'A' : [2, 5], 'B' : [1, 7]})
you take a row
df_1_record = df[:1]
and convert df_1_record to a csv like this:
import io
from io import StringIO
csv_file = io.StringIO()
# by default sagemaker expects comma seperated
df_1_record.to_csv(csv_file, sep=",", header=False, index=False)
my_payload_as_csv = csv_file.getvalue()
my_payload_as_csv looks like
'2,1\n'
then you can invoke the sagemaker endpoint
import boto3
client = boto3.client('sagemaker-runtime')
response = client.invoke_endpoint(
EndpointName="my-sagemaker-endpoint-name",
Body= my_payload_as_csv,
ContentType = 'text/csv')

Answer 2

#VincentCleas's answer was good. But, If you want to construct csv-payload without installing pandas, do this:
import boto3
csv_buffer = open('<file-name>.csv')
my_payload_as_csv = csv_buffer.read()
client = boto3.client('sagemaker-runtime')
response = client.invoke_endpoint(
EndpointName="my-sagemaker-endpoint-name",
Body= my_payload_as_csv,
ContentType = 'text/csv')