CODEWITHSUNDEEP
pythonlistassociative-array
nubme
nubme

Reputation: 3167

Python: Adding elements to an dict list or associative array

Im trying to add elements to a dict list (associative array), but every time it loops, the array overwrites the previous element. So i just end up with an array of size 1 with the last element read. I verified that the keys ARE changing every time.

array=[]
for line in open(file):
  result=prog.match(line)
  array={result.group(1) : result.group(2)}

any help would be great, thanks =]

Upvotes: 3

Views: 12640

Answers (3)

eumiro
eumiro

Reputation: 213015

Maybe even more Pythonic:

with open(filename, 'r') as f:
    array = dict(prog.match(line).groups() for line in f)

or, if your prog matches more groups:

with open(filename, 'r') as f:
    array = dict(prog.match(line).groups()[:2] for line in f)

Upvotes: 0

pyfunc
pyfunc

Reputation: 66729

Your solution is incorrect; the correct version is:

array={}
for line in open(file):
  result=prog.match(line)
  array[result.group(1)] = result.group(2)

Issues with your version:

  1. associative arrays are dicts and empty dicts = {}
  2. arrays are list , empty list = []
  3. You are pointing the array to new dictionary every time.

This is like saying:

array={result.group(1) : result.group(2)}
array={'x':1}
array={'y':1}
array={'z':1}
....

array remains one element dict

Upvotes: 6

Maciej Kucharz
Maciej Kucharz

Reputation: 1443

array=[]
for line in open(file):
  result=prog.match(line)
  array.append({result.group(1) : result.group(2)})

Or:

array={}
for line in open(file):
  result=prog.match(line)
  array[result.group(1)] = result.group(2)

Upvotes: 0

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