problem in reading indices

[Xavier Barthelemy]

Hi all

I'm becoming mad, because I can't see what's wrong:

I am constructing a GUI, to plot some data.
so let's have a look of what's wrong:



in my code I have a variable named choice.current which is the
current selection of the i-th Listbox object. it is a tuple, with one
element.

so when I write

print type(i),type(choice.current)
I have: int and tuple

print type(i),type(choice.current[0])
I have: int and str

print type(i),type(int(choice.current[0]))
I have: int and int

so when I call another array with these indices
ArrayWithData[i,int(choice.current[0])]

I have the following error: TypeError: list indices must be integers

so I tried an intermediate value, because sometimes, the oneliner code
doesn't work, so with an intermediate passage:
value=int(choice.current[0])
ArrayWithData[i,value]

I have the same error

and I don't understand why. What's wrong?
May anyone have an idea?
Xavier

pm:
and print type(ArrayWithData), ArrayWithData gives me
<type 'list'> [array([ 2.01, 5.01]),...]

 

[Bruno Desthuilliers]

Xavier Barthelemy a écrit :

Hi all

I'm becoming mad, because I can't see what's wrong:

I am constructing a GUI, to plot some data.
so let's have a look of what's wrong:



in my code I have a variable named choice.current which is the
current selection of the i-th Listbox object. it is a tuple, with one
element.

so when I write

print type(i),type(choice.current)
I have: int and tuple

print type(i),type(choice.current[0])
I have: int and str

print type(i),type(int(choice.current[0]))
I have: int and int

so when I call another array with these indices
ArrayWithData[i,int(choice.current[0])]

I have the following error: TypeError: list indices must be integers

the syntax for list subscripting is:

thelist[index]

not:

thelist[index,index]


If the item at thelist[index] is itself an object that supports
subscripting and you want to subscript it to (which seems to be the case
here), the syntax is:

thelist[index][subindex]

IOW, try with:

ArrayWithData[int(choice.current[0])]

so I tried an intermediate value, because sometimes, the oneliner code
doesn't work,

if you're sure that choice.current[0] exists and can be passed to the
int type, there's no reason for the oneliner to behave differently.

HTH

 

[Bjoern Schliessmann]

so when I call another array with these indices
ArrayWithData[i,int(choice.current[0])]

You don't "call" "arrays" "with indices". You are indexing the list
ArrayWithData using the index "i,int(blah)" which is invalid.
Indices must be integers, not comma seperated values.

so I tried an intermediate value, because sometimes, the oneliner
code doesn't work, so with an intermediate passage:
value=int(choice.current[0])
ArrayWithData[i,value]

I have the same error

and I don't understand why. What's wrong?
May anyone have an idea?

I'm afraid not! You didn't specify at all what you'd like to achieve
(just "it doesn't work! why?), and clairvoyance isn't as easy as it
looks.

If you want to slice, don't use Perl syntax. Python uses a colon for
index separation to eliminate ambiguities.

some_elements = my_list[3:10]

Regards,


Björn