Allow importing pandas without setuptools

doc/source/install.rst

@@ -302,6 +302,8 @@ Optional Dependencies
 * Google's `python-gflags <http://code.google.com/p/python-gflags/>`__
   and `google-api-python-client <http://github.com/google/google-api-python-client>`__
    * Needed for :mod:`~pandas.io.gbq`
+* `setuptools <https://pypi.python.org/pypi/setuptools/>`__
+   * Needed for :mod:`~pandas.io.gbq` (specifically, it utilizes `pkg_resources`)
 * `httplib2 <http://pypi.python.org/pypi/httplib2>`__
    * Needed for :mod:`~pandas.io.gbq`
 * One of the following combinations of libraries is needed to use the

pandas/io/gbq.py

@@ -6,7 +6,6 @@
 import uuid
 
 import numpy as np
-import pkg_resources
 
 from distutils.version import LooseVersion
 from pandas import compat
@@ -20,46 +19,54 @@
 _GOOGLE_FLAGS_INSTALLED = False
 _GOOGLE_FLAGS_VALID_VERSION = False
 _HTTPLIB2_INSTALLED = False
+_SETUPTOOLS_INSTALLED = False
 
 if not compat.PY3:
-    
+
     try:
-        from apiclient.discovery import build
-        from apiclient.http import MediaFileUpload
-        from apiclient.errors import HttpError
+        import pkg_resources
+        _SETUPTOOLS_INSTALLED = True
+    except ImportError:
+        _SETUPTOOLS_INSTALLED = False
+
+    if _SETUPTOOLS_INSTALLED:
+        try:
+            from apiclient.discovery import build
+            from apiclient.http import MediaFileUpload
+            from apiclient.errors import HttpError
 
-        from oauth2client.client import OAuth2WebServerFlow
-        from oauth2client.client import AccessTokenRefreshError
-        from oauth2client.client import flow_from_clientsecrets
-        from oauth2client.file import Storage
-        from oauth2client.tools import run
-        _GOOGLE_API_CLIENT_INSTALLED=True
-        _GOOGLE_API_CLIENT_VERSION = pkg_resources.get_distribution('google-api-python-client').version
+            from oauth2client.client import OAuth2WebServerFlow
+            from oauth2client.client import AccessTokenRefreshError
+            from oauth2client.client import flow_from_clientsecrets
+            from oauth2client.file import Storage
+            from oauth2client.tools import run
+            _GOOGLE_API_CLIENT_INSTALLED=True
+            _GOOGLE_API_CLIENT_VERSION = pkg_resources.get_distribution('google-api-python-client').version
 
-        if LooseVersion(_GOOGLE_API_CLIENT_VERSION >= '1.2.0'):
-            _GOOGLE_API_CLIENT_VALID_VERSION = True
+            if LooseVersion(_GOOGLE_API_CLIENT_VERSION >= '1.2.0'):
+                _GOOGLE_API_CLIENT_VALID_VERSION = True
 
-    except ImportError:
-        _GOOGLE_API_CLIENT_INSTALLED = False
+        except ImportError:
+            _GOOGLE_API_CLIENT_INSTALLED = False
 
 
-    try:
-        import gflags as flags
-        _GOOGLE_FLAGS_INSTALLED = True
+        try:
+            import gflags as flags
+            _GOOGLE_FLAGS_INSTALLED = True
 
-        _GOOGLE_FLAGS_VERSION = pkg_resources.get_distribution('python-gflags').version
+            _GOOGLE_FLAGS_VERSION = pkg_resources.get_distribution('python-gflags').version
 
-        if LooseVersion(_GOOGLE_FLAGS_VERSION >= '2.0.0'):
-            _GOOGLE_FLAGS_VALID_VERSION = True
+            if LooseVersion(_GOOGLE_FLAGS_VERSION >= '2.0.0'):
+                _GOOGLE_FLAGS_VALID_VERSION = True
 
-    except ImportError:
-        _GOOGLE_FLAGS_INSTALLED = False
+        except ImportError:
+            _GOOGLE_FLAGS_INSTALLED = False
 
-    try:
-        import httplib2
-        _HTTPLIB2_INSTALLED = True
-    except ImportError:
-        _HTTPLIB2_INSTALLED = False
+        try:
+            import httplib2
+            _HTTPLIB2_INSTALLED = True
+        except ImportError:
+            _HTTPLIB2_INSTALLED = False
 
 
 logger = logging.getLogger('pandas.io.gbq')
@@ -296,10 +303,14 @@ def _test_imports():
     _GOOGLE_FLAGS_INSTALLED
     _GOOGLE_FLAGS_VALID_VERSION
     _HTTPLIB2_INSTALLED
+    _SETUPTOOLS_INSTALLED
 
     if compat.PY3:
         raise NotImplementedError("Google's libraries do not support Python 3 yet")
 
+    if not _SETUPTOOLS_INSTALLED:
+        raise ImportError('Could not import pkg_resources (setuptools).')
+
     if not _GOOGLE_API_CLIENT_INSTALLED:
         raise ImportError('Could not import Google API Client.')