Re: [Tutor] Making a dictionary of dictionaries from csv file
Judith Flores [EMAIL PROTECTED] wrote
I have been trying to create a dictionary of dictionaries
(and more dictionaries) from a csv file.
Your code below suffers from sloppiness in the number of []
which makes it hard to know exactly what the problem might be.
But in principle what you are doing is fine and should work
beyond 2 levels.
However I would suggest that it might be esier to use classes
instead of dictionaries. Dictionaries are fine for many things but
can become a bit tortuous to navigate and maintain.
NameDayweighttemp
name114537
name135536
name215936
I assume there should be some commas (or other separators)
in there? Othewise how do you expect the csv module to separate
the data?
row={}
maindict={}
reader=DictReader(f)
for row in reader:
maindict[row['Name']=row
I assume you have a second closing ] after Name?
Also you are overwriting the row for each name. So you only
store the last entry. So you need to separate the data further.
Something like
maindict[row[name]] [row[day]] = (row.weight, row,temp)
Which would look like
{name1: {day1: (w,t), day2 : (w,t),
day2: (w,t)},
name2: {day3: (w,t)
Which looks a bit like what you want I think?
then I can access the weight of a given name like this:
wg=int(maindict[['name1']['weight'])
I assume thats a single open { before name1?
My question is the following:
How can I convert the csv to a dictionary that would have the
following structure?
maindict = {
'name1' : {
'Day' : {
1 : { 'weight' : '45', 'temp' : '37' } ,
3 : { 'weight' : '55', 'temp' : '36' }
}
},
See above
HTH,
--
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld
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Re: [Tutor] Making a dictionary of dictionaries from csv file
On Wed, Dec 3, 2008 at 3:34 AM, Alan Gauld [EMAIL PROTECTED] wrote: Also you are overwriting the row for each name. So you only store the last entry. So you need to separate the data further. Something like maindict[row[name]] [row[day]] = (row.weight, row,temp) This will not quite work. It will give KeyErrors because the second-level dicts don't exist in maindict. One way to fix this is to use collections.defaultdict: from collections import defaultdict maindict = defaultdict(dict) Now maindict uses an empty dictionary as its default value. For another level of nesting (the 'Day' level you show in your example) this becomes a bit more complex, see this discussion and the link: http://thread.gmane.org/gmane.comp.python.tutor/46006 Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Making a dictionary of dictionaries from csv file
How about this: def recursiveDictFactory(): return defaultdict(recursiveDictFactory) dictOfDictsOfDictsEtc = defaultdict(recursiveDictFactory) --- Richard Roadie Rich Lovely Part of the JNP|UK Famille www.theJNP.com (Sent from my iPod - please allow me a few typos: it's a very small keyboard) On 3 Dec 2008, at 11:43, Kent Johnson [EMAIL PROTECTED] wrote: On Wed, Dec 3, 2008 at 3:34 AM, Alan Gauld [EMAIL PROTECTED] wrote: Also you are overwriting the row for each name. So you only store the last entry. So you need to separate the data further. Something like maindict[row[name]] [row[day]] = (row.weight, row,temp) This will not quite work. It will give KeyErrors because the second-level dicts don't exist in maindict. One way to fix this is to use collections.defaultdict: from collections import defaultdict maindict = defaultdict(dict) Now maindict uses an empty dictionary as its default value. For another level of nesting (the 'Day' level you show in your example) this becomes a bit more complex, see this discussion and the link: http://thread.gmane.org/gmane.comp.python.tutor/46006 Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Making a dictionary of dictionaries from csv file
Dear Python community,
I have been trying to create a dictionary of dictionaries (and more
dictionaries) from a csv file. The csv file contains longitudinal data
corresponding to names. The following is just a very (very) simple example of
how the data looks:
NameDayweighttemp
name114537
name135536
name215936
name233436.5
name316637
name338736.8
So far I have written this:
from csv import *
f=open('myfile.csv',rt)
row={}
maindict={}
reader=DictReader(f)
for row in reader:
maindict[row['Name']=row
then I can access the weight of a given name like this:
wg=int(maindict[['name1']['weight'])
My question is the following:
How can I convert the csv to a dictionary that would have the following
structure?
maindict = {
'name1' : {
'Day' : {
1 : { 'weight' : '45', 'temp' : '37' } ,
3 : { 'weight' : '55', 'temp' : '36' }
}
},
'name2' : { . # and we repeat the same structure for the rest of the names.
}
From my code above you can of course guess that it doesn't make beyond the
level of name.
Thank you very much,
Judith
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