[IPython-user] Parsing issue (maybe).

[Robert Kern]

Andrea Riciputi wrote:
> Hi all,
> I've a problem here with ipython 0.6.15. I don't know if the new  
> version (0.7.0) still exhibits the same problem though. Here it is  
> the problem. I've defined a class to mimick mathematical functions  
> and in that class I've defined the special method __and__ to check if  
> 2 functions have the same dimensionality. Here it is a meaningfull  
> excerpt:
> 
> In [1]: import Functions
> 
> In [2]: x = Numeric.arange(10)
> 
> In [3]: y = Numeric.arange(5)
> 
> In [4]: z1 = x[:,Numeric.NewAxis] + y
> 
> In [5]: z2 = x[:,Numeric.NewAxis] - y
> 
> In [6]: foo = Functions.Function([x,y], z1)
> 
> In [7]: bar = Functions.Function([x,y], z2)
> 
> In [8]: foo & bar
> ------> foo(& bar)
> ------------------------------------------------------------
>     File "<console>", line 1
>       foo(& bar)
>           ^
> SyntaxError: invalid syntax

Turn off %autocall. With %autocall on, ipython recognizes the first token as
referring to a callable (I presume Function's are callable), and so it tries to
transform the command into a function call. Of course, this doesn't work in this
case.

I usually have %autocall off for this reason.

-- 
Robert Kern
robert.kern at gmail.com

"In the fields of hell where the grass grows high
 Are the graves of dreams allowed to die."
  -- Richard Harter