Getting an unexpected NameError in pycassaShell when invoking one function from another

Question

I'm playing with pycassaShell (as part of the Cassandra and the Twissandra tutorial). When trying to add two functions inside the shell, and call one from the other I get an error that the Name is not recognized.

This is probably something very simple, but I did not find how to do this.

The pycassaShell looks like:

In [3]: def aaa(): print 5
In [4]: aaa()
5

In [5]: def bbb(): aaa()

In [6]: bbb()
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
...
NameError: global name 'aaa' is not defined

Brag

Can you include the elided output in the traceback (assuming that there is some)? There might be something useful there and I don't have Cassandra/pycassa set up at the moment, so I can't check for myself. – Sidoon

Works perfectly in pure IPython. – Polyphone

Works fine in pure python as well – Piassava

Had similar problems myself with django shell. Looks like it may be a bug in ipyrhon: github.com/ipython/ipython/issues/2532 – Brigade

I agree: It afects my django shell and pycassaShell - each of which use ipython – Mombasa

Answer 1

This is an issue with the way Pycassa is embedding IPython. This is the same problem @Benjamin White references regarding Django's IPython use. Django fixed the bug by accepting a pull request from an IPython core dev.

I took the liberty to file an issue with Pycassa. Hopefully they'll be able to investigate why a similar fix won't work for them.

Autolysin

Answer 2

This is odd. I don't know why it is happening, but try this:

def aaa(): print 5

def bbb():
    global aaa
    aaa()

Piassava

could you run dir() and tell us the output? In python it should say ['__builtins__', '__doc__', '__name__', '__package__', 'aaa', 'bbb']. – Piassava

@Brag can you please run dir()? – Piassava

Answer 3

Is it possible that you are using Python 3? If you are, visit http://docs.python.org/release/3.0.1/whatsnew/3.0.html for the list of changes.

It worked both in IPython and regular python v2.7.

Riboflavin

Answer 4

What about:

def aaa(self): print 5 
def bbb(): self.aaa

That's what I do when I get Name Errors...

Brigettebrigg