How to detect sampling in Google Analytics API v4? - google-analytics-api

Question

Google Analytics Core Reporting API v3 has the containsSampledData field we can use to see if results have been sampled. How is this done in v4? Can't find anything about it in the documentation.

Answer 1

There are two fields you will need to read from the API response:
reportData.samplesReadCounts: If the results are sampled, this returns the total number of samples read, one entry per date range. If the results are not sampled this field will not be defined.
resportData.samplingSpaceSizes: If the results are sampled, this returns the total number of samples present, one entry per date range. If the results are not sampled this field will not be defined.
GAV4 - Analytics Reporting API V4 Compatibility Library Analytics
The API release was accompanied by the release of a compatibility library which converts Core Reporting API V3 requests into Analytics Reporting API V4 requests and V4 responses into V3 responses. To determine if the response was sampled you simply need to check if these fields are set in the response:
# Calculated sampling.
report_data = report.get('data', {})
sample_sizes = report_data.get('samplesReadCounts', [])
sample_spaces = report_data.get('samplingSpaceSizes', [])
if sample_sizes and sample_spaces:
data['sampleSize'] = sample_sizes[0]
data['sampleSpace'] = sample_spaces[0]
data['containsSampledData'] = True
else:
data['containsSampledData'] = False
Migrating from V3 to V4
There is a detailed Migration guide and Developer guide which describe how to determine if a V4 response contains sampled data.