dict indexed by lists - ?

[Alexander Zatvornitskiy]

Hello All!

I'am trying to make something like this:

CPT={ ['b0','c0']:1, ['b0','c1']:0, ['b1','c0']:3, ['b1','c1']:1 }

but python says "TypeError: list objects are unhashable"

I can replace list with touple: CPT={ ('b0','c0'):1, ('b0','c1'):0, ...and so
on. But, where is one problem: indexes (or, more precisely, keys) are generated
dynamically, like code below! I can't do it with touples.


key=[]
for up in uplinks:
key.append(up.state(0))


and, later, modifying it like this:
key[2]=up.next_state()
...
print CPT[key]

Any suggestions?


Alexander, (e-mail address removed)

 

[Steven Bethard]

Hello All!

I'am trying to make something like this:

CPT={ ['b0','c0']:1, ['b0','c1']:0, ['b1','c0']:3, ['b1','c1']:1 }

but python says "TypeError: list objects are unhashable"

I can replace list with touple: CPT={ ('b0','c0'):1, ('b0','c1'):0, ...and so
on. But, where is one problem: indexes (or, more precisely, keys) are generated
dynamically, like code below! I can't do it with touples.


key=[]
for up in uplinks:
key.append(up.state(0))


and, later, modifying it like this:
key[2]=up.next_state()
...
print CPT[key]

Any suggestions?

You can manually add the tuple calls:

CPT = {('b0','c0'):1, ('b0','c1'):0, ('b1','c0'):3, ('b1','c1'):1}
...
key = [up.state(0) for up in uplinks]
...
key[2] = up.next_state()
...
print CPT[tuple(key)]

I've only added the tuple call when you actually access CPT, but
depending on your code, you might find that you can make the tuple call
earlier. For example, the following code should work:

CPT={('b0','c0'):1, ('b0','c1'):0, ('b1','c0'):3, ('b1','c1'):1}
...
key = tuple([up.state(0) for up in uplinks])
...
print CPT[key]

where basically you convert key back to a tuple any time it's changed.

STeVe

 

[Alexander Zatvornitskiy]

ðÒÉ×ÅÔ All!

04 ÆÅ×ÒÁÌÑ 2005 × 02:47, Alexander Zatvornitskiy × Ó×ÏÅÍ ÐÉÓØÍÅ Ë All ÐÉÓÁÌ:
AZ> I'am trying to make something like this:
AZ> CPT={ ['b0','c0']:1, ['b0','c1']:0, ['b1','c0']:3, ['b1','c1']:1 }

Thanks, I fix it - i use lists.

AZ> and, later, modifying it like this:
AZ> key[2]=up.next_state()

replaced with:
k=k[:cur_idx-1]+up.next_state()+k[cur_id+1:]

AZ> ...
AZ> print CPT[key]

AZ> Any suggestions?


AZ> Alexander, (e-mail address removed)


Alexander, (e-mail address removed)