pythonPackages.ipython: support python2

Fixes #25234

pkgs/development/python-modules/ipython/5.nix

@@ -0,0 +1,65 @@
+{ lib
+, stdenv
+, buildPythonPackage
+, fetchPypi
+, pythonOlder
+# Build dependencies
+, glibcLocales
+# Test dependencies
+, nose
+, pygments
+, testpath
+, isPy27
+, mock
+# Runtime dependencies
+, backports_shutil_get_terminal_size
+, jedi
+, decorator
+, pathlib2
+, pickleshare
+, requests2
+, simplegeneric
+, traitlets
+, prompt_toolkit
+, pexpect
+, appnope
+}:
+
+buildPythonPackage rec {
+  pname = "ipython";
+  version = "5.3.0";
+  name = "${pname}-${version}";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "bf5e615e7d96dac5a61fbf98d9e2926d98aa55582681bea7e9382992a3f43c1d";
+  };
+
+  prePatch = stdenv.lib.optionalString stdenv.isDarwin ''
+    substituteInPlace setup.py --replace "'gnureadline'" " "
+  '';
+
+  buildInputs = [ glibcLocales ];
+
+  checkInputs = [ nose pygments testpath ] ++ lib.optional isPy27 mock;
+
+  propagatedBuildInputs = [
+    backports_shutil_get_terminal_size decorator pickleshare prompt_toolkit
+    simplegeneric traitlets requests2 pathlib2 pexpect
+  ] ++ lib.optionals stdenv.isDarwin [ appnope ];
+
+  LC_ALL="en_US.UTF-8";
+
+  doCheck = false; # Circular dependency with ipykernel
+
+  checkPhase = ''
+    nosetests
+  '';
+
+  meta = {
+    description = "IPython: Productive Interactive Computing";
+    homepage = http://ipython.org/;
+    license = lib.licenses.bsd3;
+    maintainers = with lib.maintainers; [ bjornfor jgeerds orivej lnl7 ];
+  };
+}

pkgs/development/python-modules/ipython/default.nix

@@ -8,8 +8,6 @@
 # Test dependencies
 , nose
 , pygments
-, isPy27
-, mock
 # Runtime dependencies
 , jedi
 , decorator
@@ -37,7 +35,7 @@ buildPythonPackage rec {
 
   buildInputs = [ glibcLocales ];
 
-  checkInputs = [ nose pygments ] ++ lib.optional isPy27 mock;
+  checkInputs = [ nose pygments ];
 
   propagatedBuildInputs = [
     jedi

pkgs/top-level/python-packages.nix

@@ -13243,7 +13243,12 @@ in {
 
   ipyparallel = callPackage ../development/python-modules/ipyparallel { };
 
-  ipython = callPackage ../development/python-modules/ipython { };
+  # Newer versions of IPython no longer support Python 2.7.
+  ipython = if isPy27 then self.ipython_5 else self.ipython_6;
+
+  ipython_5 = callPackage ../development/python-modules/ipython/5.nix { };
+
+  ipython_6 = callPackage ../development/python-modules/ipython { };
 
   ipython_genutils = buildPythonPackage rec {
     version = "0.2.0";