Ren-py: Why doesn't this work?

Question

I want the images to be loaded depending on a variable "ImgVal"

$ ImgVal = []
$ image bob = "b_neutral_%s.png" % ImgVal
$ image bob_sad = "b_sad_%s.png" % ImgVal
$ image bob_happy = "b_happy_%s.png" % ImgVal

Answer 1

The value passed by the % operator has to be of type string (or a dictionary, if you use %(val_name)s instead of %s).

For example:

ImgVal = 1
# some calculation to evaluate Imgval
print "b_neutral_%s.png" % str(ImgVal) # cast ImgVal from int to str

Note that if you want to use a array you'll need some construct like this:

ImgVal = [1, 2, 3, 4]
for i in ImgVal:
    print "b_neutral_%s.png" % str(i)

Edit:

I've never worked with renpy, but looking in the documentation about using python, you are using the $ sign incorrectly, you should only use it for raw python code. The % operator is python only, therefore you'll have to use it and evaluate the string, then pass it to renpy. This could probably work:

$ ImgVal = "h1c1"
$ img_str = "b_neutral_%s.png" % ImgVal
image bob = img_str
$ img_str = "b_sad_%s.png" % ImgVal
image bob_sad = img_str
$ img_str = "b_happy_%s.png" % ImgVal
image bob_happy = img_str

The only thing I can tell you for sure is that you were using $ incorrectly and that your string formatting was wrong in your first example.