[SciPy-User] numpy array assignment

[marco cammarata]

Antonino Ingargiola <tritemio <at> gmail.com> writes:

> 
> 
> On Thu, Apr 17, 2014 at 7:59 AM, marco cammarata <marcocamma <at> 
gmail.com> wrote: 
> 
> 
> 
> 
> For the moment I ended up doing something really really inelegant:
>   res = result_of_long_calculation_returning_the_right_shape()
>   s = "out[" + (":,")*axis + "i" + (",:")*(nDim-axis-1) + "]=res"
>   exec(s)
> 
> 
> When you do a[:, :, :], that's just syntactic sugar for a[(slice(None), 
slice(None), slice(None),)] (note that slice(None) means take all elements). 
In other words, the index of a ndarray is a tuple of objects/slices.
> 
> You can build the tuple programmatically. Another example:
> 
>     import numpy as np
>     a = np.arange(1000).reshape(10, 5, 20)
>     index = (slice(None), slice(0, 1), slice(None))
> 
>     a[index] = 3
>     a
> 
> 
> Cheers,
> Antonio
> 
>  
> 
> 
> 
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Antonio,

thanks for your comment.
Indeed your solution is better than mine because avoid the exec but would 
still require the construction of the tuple by checking the axis and the 
number of dimension.

What I was really looking for is a more general (compact) solution.

Thanks anyway,
ciao
marco