instructions for common usage error, closes #63

ivanov · ivanov · commit ff8f88f3fe51 · 2013-08-29T15:34:24.000-07:00
diff --git a/ftplugin/python/ipy.vim b/ftplugin/python/ipy.vim
@@ -77,12 +77,25 @@ except NameError:
     kc = None
     pid = None
 
+_install_instructions = """You *must* install IPython into the Python that
+your vim is linked against. If you are seeing this message, this usually means
+either (1) installing IPython using the system Python that vim is using, or
+(2) recompiling Vim against the Python where you already have IPython
+installed. This is only a requirement to allow Vim to speak with an IPython
+instance using IPython's own machinery. It does *not* mean that the IPython
+instance with which you communicate via vim-ipython needs to be running the
+same version of Python.
+"""
 def km_from_string(s=''):
     """create kernel manager from IPKernelApp string
     such as '--shell=47378 --iopub=39859 --stdin=36778 --hb=52668' for IPython 0.11
     or just 'kernel-12345.json' for IPython 0.12
     """
     from os.path import join as pjoin
+    try:
+        import IPython
+    except ImportError:
+        raise ImportError("Could not find IPython. " + _install_instructions)
     from IPython.config.loader import KeyValueConfigLoader
     from Queue import Empty
     try:
