2

I have a csv file that I've turned into a list() so that I can iterate over it to do some simple transformations with the data, however when I try to get the output I only get the key for each of the items (when what I need are the values).

The code I'm using right now is as follows (slightly truncated for clarity):

lines = list(csvdataFishes)
while (startTime + 30) > timeToEpoch(currLine['timestamp']) >= startTime:
    cx = someFunction1()
    uf = someFunction2()
    rf = someFunction3()
    pc = someFunction4()
    outline = [k for k in lines[i] if k is not ''] + [cx,uf,rf,pc]
    print ','.join(outline)
    i += 1
    currLine = lines[i]
startTime = startTime + 30

If I do a simple print lines[i] I get something like:

{
'adjusted timestamp': '2014-08-23 17:20:05.43000', 
'fishType': 'small green fish', 
'playerID': '3', 
'timestamp': '2014-08-23 16:21:05.430000-05:00', 
'targetID': '34', 
'lights': '1', 
'event': 'MakeSpawnFish'
}

but the output of print ','.join(outline) just gives me the keys for the [k for k in lines[i] if k is not ''] and the correct output for [cx,uf,rf,pc] (like so):

adjusted timestamp,fishType,playerID,timestamp,targetID,lights,event,1,1,2,1

What I'm wondering is how I get it to give the values (and not the key) for the [k for k in lines[i] if k is not '']

Mike
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3 Answers3

4

You can use the keys and values builtins:

>>> [k for k in lines[i].keys() if k is not '']
['fishType', 'timestamp', 'event', 'targetID', 'playerID', 'lights', 'adjusted timestamp']

and 

>>> [k for k in lines[i].values() if k is not '']
['small green fish', '2014-08-23 16:21:05.430000-05:00', 'MakeSpawnFish', '34', '3', '1', '2014-08-23 17:20:05.43000']

These will iterate over the dictionary's keys and values. Check out the dictionary documentation here.

Zach Gates
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  • using lines[i].iterkeys() and lines[i].itervalues() might be better? – Xiaotian Pei May 10 '15 at 17:59
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    See [this question](http://stackoverflow.com/questions/3616721/iterating-over-dictionary-items-values-keys-in-python-3). @XiaotianPei I used `keys` and `values` because they are Python 2 and Python 3 compatible. – Zach Gates May 10 '15 at 18:00
  • This is great - similar to 1.618's answer – Mike May 10 '15 at 18:11
2

Lines is a list of dicts. If you iterate over a dict, you get its keys. To get the values instead, use dict.values(). So you need to change this line:

outline = [k for k in lines[i] if k is not ''] + [cx,uf,rf,pc]

to

outline = [k for k in lines[i].values() if k is not ''] + [cx,uf,rf,pc]
1.618
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0

Do you mean

[ lines[k] for k in lines if k is not '']

Test

>>> lines = {
... 'adjusted timestamp': '2014-08-23 17:20:05.43000', 
... 'fishType': 'small green fish', 
... 'playerID': '3', 
... 'timestamp': '2014-08-23 16:21:05.430000-05:00', 
... 'targetID': '34', 
... 'lights': '1', 
... 'event': 'MakeSpawnFish'
... }

>>> ",".join( [ lines[k] for k in lines if k is not ''] + ["1", "1", "2", "1"])
'2014-08-23 17:20:05.43000,small green fish,3,2014-08-23 16:21:05.430000-05:00,34,1,MakeSpawnFish,1,1,2,1'
nu11p01n73R
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