scikit-learn · jnothman · Jul 31, 2018 · Jul 17, 2018 · Jul 17, 2018 · Jul 17, 2018
diff --git a/doc/developers/contributing.rst b/doc/developers/contributing.rst
@@ -140,6 +140,14 @@ feedback:
   your **Python, scikit-learn, numpy, and scipy versions**. This information
   can be found by running the following code snippet::
 
+    >>> import sklearn
+    >>> sklearn.show_versions()  # doctest: +SKIP
+
+  .. note::
+
+    This utility function is only available in scikit-learn v0.20+.
+    For previous versions, one has to explicitly run::
+
      import platform; print(platform.platform())
      import sys; print("Python", sys.version)
      import numpy; print("NumPy", numpy.__version__)

diff --git a/doc/developers/tips.rst b/doc/developers/tips.rst
@@ -121,15 +121,11 @@ Issue: Self-contained example for bug
 Issue: Software versions
     ::
 
-        To help diagnose your issue, could you please paste the output of:
+        To help diagnose your issue, please paste the output of:
         ```py
-        import platform; print(platform.platform())
-        import sys; print("Python", sys.version)
-        import numpy; print("NumPy", numpy.__version__)
-        import scipy; print("SciPy", scipy.__version__)
-        import sklearn; print("Scikit-Learn", sklearn.__version__)
+        import sklearn; sklearn.show_versions()
         ```
-        ? Thanks.
+        Thanks.
 
 Issue: Code blocks
     ::

diff --git a/doc/modules/classes.rst b/doc/modules/classes.rst
@@ -48,6 +48,7 @@ Functions
    config_context
    get_config
    set_config
+   show_versions
 
 .. _calibration_ref:
 

diff --git a/doc/whats_new/v0.20.rst b/doc/whats_new/v0.20.rst
@@ -217,6 +217,12 @@ Misc
   exposed in :mod:`sklearn.utils`.
   :issue:`11166`by `Gael Varoquaux`_
 
+- A utility method :func:`sklearn.show_versions()` was added to print out
+  information relevant for debugging. It includes the user system, the
+  Python executable, the version of the main libraries and BLAS binding
+  information.
+  :issue:`11596` by :user:`Alexandre Boucaud <aboucaud>`
+
 Enhancements
 ............
 

diff --git a/sklearn/__init__.py b/sklearn/__init__.py
@@ -62,6 +62,8 @@
 else:
     from . import __check_build
     from .base import clone
+    from .utils._show_versions import show_versions
+
     __check_build  # avoid flakes unused variable error
 
     __all__ = ['calibration', 'cluster', 'covariance', 'cross_decomposition',
@@ -74,7 +76,8 @@
                'preprocessing', 'random_projection', 'semi_supervised',
                'svm', 'tree', 'discriminant_analysis', 'impute', 'compose',
                # Non-modules:
-               'clone', 'get_config', 'set_config', 'config_context']
+               'clone', 'get_config', 'set_config', 'config_context',
+               'show_versions']
 
 
 def setup_module(module):

diff --git a/sklearn/utils/_show_versions.py b/sklearn/utils/_show_versions.py
@@ -0,0 +1,119 @@
+"""
+Utility methods to print system info for debugging
+
+adapted from :func:`pandas.show_versions`
+"""
+# License: BSD 3 clause
+
 import platform
+import sys
+import importlib
+
+
+def _get_sys_info():
+    """System information
+
+    Return
+    ------
+    sys_info : dict
+        system and Python version information
+
+    """
+    python = sys.version.replace('\n', ' ')
+
+    blob = [
+        ("python", python),
+        ('executable', sys.executable),
+        ("machine", platform.platform()),
+    ]
+
+    return dict(blob)
+
+
+def _get_deps_info():
+    """Overview of the installed version of main dependencies
+
+    Returns
+    -------
+    deps_info: dict
+        version information on relevant Python libraries
+
+    """
+    deps = [
+        "pip",
+        "setuptools",
+        "sklearn",
+        "numpy",
+        "scipy",
+        "Cython",
+        "pandas",
+    ]
+
+    def get_version(module):
+        return module.__version__
+
+    deps_info = {}
+
+    for modname in deps:
+        try:
+            if modname in sys.modules:
+                mod = sys.modules[modname]
+            else:
+                mod = importlib.import_module(modname)
+            ver = get_version(mod)
+            deps_info[modname] = ver
+        except ImportError:
+            deps_info[modname] = None
+
+    return deps_info
+
+
+def _get_blas_info():
+    """Information on system BLAS
+
+    Uses the `scikit-learn` builtin method
+    :func:`sklearn._build_utils.get_blas_info` which may fail from time to time
+
+    Returns
+    -------
+    blas_info: dict
+        system BLAS information
+
+    """
+    from .._build_utils import get_blas_info
+
+    cblas_libs, blas_dict = get_blas_info()
+
+    macros = ['{key}={val}'.format(key=a, val=b)
+              for (a, b) in blas_dict.get('define_macros', [])]
+
+    blas_blob = [
+        ('macros', ', '.join(macros)),
+        ('lib_dirs', ':'.join(blas_dict.get('library_dirs', ''))),
+        ('cblas_libs', ', '.join(cblas_libs)),
+    ]
+
+    return dict(blas_blob)
+
+
+def show_versions():
+    "Print useful debugging information"
+
+    sys_info = _get_sys_info()
+    deps_info = _get_deps_info()
+    blas_info = _get_blas_info()
+
+    print('\nSystem')
+    print('------')
+    for k, stat in sys_info.items():
+        print("{k:>10}: {stat}".format(k=k, stat=stat))
+
+    print('\nBLAS')
+    print('----')
+    for k, stat in blas_info.items():
+        print("{k:>10}: {stat}".format(k=k, stat=stat))
+
+    print('\nPython deps')
+    print('-----------')
+    for k, stat in deps_info.items():
+        print("{k:>10}: {stat}".format(k=k, stat=stat))
diff --git a/sklearn/utils/tests/test_print_versions.py b/sklearn/utils/tests/test_print_versions.py
@@ -0,0 +1,32 @@
+
+from sklearn.utils._show_versions import _get_sys_info
+from sklearn.utils._show_versions import _get_deps_info
+from sklearn.utils._show_versions import show_versions
+
+
+def test_get_sys_info():
+    sys_info = _get_sys_info()
+
+    assert 'python' in sys_info
+    assert 'executable' in sys_info
+    assert 'machine' in sys_info
+
+
+def test_get_deps_info():
+    deps_info = _get_deps_info()
+
+    assert 'pip' in deps_info
+    assert 'setuptools' in deps_info
+    assert 'sklearn' in deps_info
+    assert 'numpy' in deps_info
+    assert 'scipy' in deps_info
+    assert 'Cython' in deps_info
+    assert 'pandas' in deps_info
+
+
+def test_show_versions_with_blas(capsys):
+    show_versions()
+    out, err = capsys.readouterr()
+    assert 'python' in out
+    assert 'numpy' in out
+    assert 'BLAS' in out