DOC update min required versions in some remaining docs (scikit-learn…

…#12778)

README.rst

@@ -14,9 +14,6 @@
 .. |CircleCI| image:: https://circleci.com/gh/scikit-learn/scikit-learn/tree/master.svg?style=shield&circle-token=:circle-token
 .. _CircleCI: https://circleci.com/gh/scikit-learn/scikit-learn
 
-.. |Python27| image:: https://img.shields.io/badge/python-2.7-blue.svg
-.. _Python27: https://badge.fury.io/py/scikit-learn
-
 .. |Python35| image:: https://img.shields.io/badge/python-3.5-blue.svg
 .. _Python35: https://badge.fury.io/py/scikit-learn
 
@@ -50,15 +47,15 @@ Dependencies
 
 scikit-learn requires:
 
-- Python (>= 2.7 or >= 3.4)
-- NumPy (>= 1.8.2)
-- SciPy (>= 0.13.3)
+- Python (>= 3.5)
+- NumPy (>= 1.11.0)
+- SciPy (>= 0.17.0)
 
-**Scikit-learn 0.20 is the last version to support Python2.7.**
-Scikit-learn 0.21 and later will require Python 3.5 or newer.
+**Scikit-learn 0.20 was the last version to support Python2.7.**
+Scikit-learn 0.21 and later require Python 3.5 or newer.
 
-For running the examples Matplotlib >= 1.4 is required. A few examples
-require scikit-image >= 0.11.3, a few examples require pandas >= 0.17.1
+For running the examples Matplotlib >= 1.5.1 is required. A few examples
+require scikit-image >= 0.12.3, a few examples require pandas >= 0.18.0
 and a few example require joblib >= 0.11.
 
 scikit-learn also uses CBLAS, the C interface to the Basic Linear Algebra

doc/developers/contributing.rst

@@ -891,18 +891,8 @@ in the examples.
 Python versions supported
 -------------------------
 
-All scikit-learn code should work unchanged in both Python 2.7 and 3.4 or
-newer. Since Python 3.x is not backwards compatible, that may require changes
-to code and it certainly requires testing on both 2.7 and 3.4 or newer.
-
-For most numerical algorithms, Python 3.x support is easy:
-just remember that ``print`` is a function and
-integer division is written ``//``.
-String handling has been overhauled, though, as have parts of
-the Python standard library.
-The `six <https://pythonhosted.org/six/>`_ package helps with
-cross-compatibility and is included in scikit-learn as
-``sklearn.externals.six``.
+All scikit-learn code should work unchanged in Python 3.5 or
+newer.
 
 
 .. _code_review:

doc/install.rst

@@ -17,15 +17,15 @@ Installing the latest release
 
 Scikit-learn requires:
 
-- Python (>= 2.7 or >= 3.4),
-- NumPy (>= 1.8.2),
-- SciPy (>= 0.13.3).
+- Python (>= 3.5),
+- NumPy (>= 1.11.0),
+- SciPy (>= 0.17.0).
 
 
 .. warning::
 
-    Scikit-learn 0.20 is the last version to support Python 2.7 and Python 3.4.
-    Scikit-learn 0.21 will require Python 3.5 or newer.
+    Scikit-learn 0.20 was the last version to support Python 2.7 and Python 3.4.
+    Scikit-learn now requires Python 3.5 or newer.
 
 If you already have a working installation of numpy and scipy,
 the easiest way to install scikit-learn is using ``pip`` ::