add installation check script

.gitignore

@@ -1,3 +1,5 @@
+*~
+
 *.py[cod]
 
 # C extensions

scripts/check_installation.py

@@ -0,0 +1,55 @@
+import warnings
+import sys
+import os
+from distutils.version import StrictVersion
+
+def warn(msg):
+    print msg
+    warnings.warn(msg)
+    warn.count += 1
+warn.count = 0
+
+
+def check_import(package_name, version=None):
+    try:
+        pkg = __import__(package_name)
+    except ImportError:
+        warn("Package {0} is not available".format(package_name))
+        return
+
+    if version:
+        pkg_version = pkg.__version__.rstrip('git').rstrip('-')
+
+        if StrictVersion(str(pkg_version)) < str(version):
+            warn("Package {0} is version {1}; "
+                 "{2} or greater is recommended".format(pkg, pkg.__version__,
+                                                        version))
+
+
+# check Python version
+if not (2, 6) <= sys.version_info[:2] <= (2, 7):
+    warn("Python 2.6 - 2.7 recommended")
+
+
+# check package versions
+check_import('numpy', '1.5')
+check_import('scipy', '0.11')
+check_import('IPython', '0.13')
+check_import('matplotlib', '1.0')
+check_import('sklearn', '0.12')
+check_import('nose')
+
+
+if warn.count > 0:
+    print(" - warning count: {0}.".format(warn_count))
+    print("   Consider upgrading your Python install:")
+    print("   Anaconda is a good all-in-one option: ")
+    print("   https://store.continuum.io/".format(warn.count))
+else:
+    print(" - no warnings: Congratulations!  ")
+    print("   Your Python installation appears up-to-date!")
+    print(" - please confirm that typing ``ipython notebook`` at your terminal")
+    print("   launches a browser window to the IPython dashboard.  If not,")
+    print("   then there are other packages which must be installed.  For")
+    print("   an easy all-in-one installation, try Anaconda:")
+    print("            https://store.continuum.io/")