Concatenate a layer name with fixed text and variables

[tkemmere]

Hi all,

I'm learning Python as I go along in the Gimp. Can somebody get me going on this one please?

I have a few variables loaded with figures. (blur is for example 10 and contrast 0.15). I would like to set a layer name, so that later I can save the layer with a filename based on the layer name.

But how do I combine fixed text and variables? It must be something like this, but how exactly?

Code:

pdb.gimp_item_set_name(new_layer, "Blur "+{blur}+"contrast "+{contrast})

I would like the layer name to be "Blur 10 contrast 0.15".

I also tried with "&" but that didn't work either. Nor did it without the "{}".

Am I close? Thanks! 

[Ofnuts]

What you want to do is called string formatting. There are several forms in Python v2, and even more forms in Pythin v3. The simplest form uses the percent operator:

Code:

pdb.gimp_item_set_name(new_layer, "Blur %3.1f, contrast %2d" % (blur,contrast))

• The things after the % in the format string ("Blur %3.1f, contrast %2d") are format specifications:
  • 3.1f means at least 3 characters wide, at least one decimal and expects a floating point value
    
  • %2d means integer (base 10), at least 2 characters wide (%d would mean: just what is needed), and expects an integer
    
  • You can also find %s for string (or whatever the __str__ method returns for an object.
    
• Format specs are replaced by the values at the same position in the tuple that follows the % operator ((blur,contrast)). If you have only one format value you can skip the tuple.
  

In Pythonv3 you could use an "f-string":

Code:

pdb.gimp_item_set_name(new_layer,f'Blur: {blur:3.4f}, contrast: {contrast:d}')

but so far in Gimp you have to stick to Python v2.

[tkemmere]

Thank you Offnuts!

More complex than I expected, but...
...I understand why that is so, cause this way offers much versatility
...well explained by you!

I got it going almost immediately! 

Code:

...
[
    (PF_SLIDER, "contrast", "Contrast", 0, (0, 0.5, 0.01)),
    (PF_SLIDER, "blur", "Blur", 0, (0, 99, 1)),
]
...

pdb.gimp_item_set_name(new_layer, "Blur %2d, contrast %4.2f" % (blur,contrast))

Thanks again!