python dictionary update method

I have a list string tag.

I am trying to initialize a dictionary with the key as the tag string and values as the array index.

for i, ithTag in enumerate(tag):
    tagDict.update(ithTag=i)

The above returns me {'ithTag': 608} 608 is the 608th index

My problem is that while the i is being interpreted as a variable, Python is treating the "ithTag" as a string instead of a variable.

I'm confused, it is kind of hard to google these kind of specific questions. I hope I worded the title of this question correctly,

Thanks!

From stackoverflow freshWoWer

• You actually want to do this:

  for i, tag in enumerate(tag):
      tagDict[tag] = i
  

  The .update() method is used for updating a dictionary using another dictionary, not for changing a single key/value pair.

  From Jerub

• I think this is what you want to do:

  d = {}
  for i, tag in enumerate(ithTag):
     d[tag] = i
  

  From Mingus Rude

• Try

  tagDict[ithTag] = i
  

  From Vinko Vrsalovic

• Thanks!

  for i, tag in enumerate(tag): tagDict[tag] = i

  From freshWoWer

• If you want to be clever:

  tagDict.update(enumerate(tag))
  

  Thanks to Brian for the update. This is apparently ~5% faster than the iterative version.

  Brian : Actually, update() can take a sequence directly, so there's no need to construct an intermediate dict. Doing tagDict.update(enumerate(tag)) is actually slightly (~5%) quicker than the iterative version.
  From Claudiu

• It's a one-liner:

  tagDict = dict((tag, i) for i, tag in enumerate(tag))
  

  From Torsten Marek