add support for returning setuptools version for bigquery statistics (#…

…4209)

* add support for returning setuptools version for bigquery statistics

* don't send the data if None

* add changelog entry

news/4209.feature

@@ -0,0 +1 @@
+Add setuptools version to the statistics sent to BigQuery.

pip/download.py

@@ -28,7 +28,8 @@
 from pip.models import PyPI
 from pip.utils import (splitext, rmtree, format_size, display_path,
                        backup_dir, ask_path_exists, unpack_file,
-                       ARCHIVE_EXTENSIONS, consume, call_subprocess)
+                       ARCHIVE_EXTENSIONS, consume, call_subprocess,
+                       get_installed_version)
 from pip.utils.encoding import auto_decode
 from pip.utils.filesystem import check_path_owner
 from pip.utils.logging import indent_log
@@ -119,6 +120,10 @@ def user_agent():
     if HAS_TLS:
         data["openssl_version"] = ssl.OPENSSL_VERSION
 
+    setuptools_version = get_installed_version("setuptools")
+    if setuptools_version is not None:
+        data["setuptools_version"] = setuptools_version
+
     return "{data[installer][name]}/{data[installer][version]} {json}".format(
         data=data,
         json=json.dumps(data, separators=(",", ":"), sort_keys=True),