Re: [Tutor] Help on best way to check resence of item inside list
jarod...@libero.it wrote:
> Dear All
>
> clubA= ["mary","luke","amyr","marco","franco","lucia", "sally","genevra","
> electra"]
> clubB= ["mary","rebecca","jane","jessica","judit","sharon","lucia",
> "sally"," Castiel","Sam"]
>
> I have a list of names that I would to annotate in function of presence
> in different clubs:
>
> my input files is a long file where I have this :
>
> mary
> luke
> luigi
> jane
> jessica
> rebecca
> luis
> à
>
> with open("file.in") as p:
> mit = []
> for i in p:
>lines =i.strip("\n").split("\t")
>if (lines[0] in clubA:
> G =lines[-1] +["clubA"]
>else:
>G = lines[-1] +["no"]
> mit.append(G)
>
>
> for i in mit:
>if i.strip("\n").split("\t")[0] in clubB:
> G =lines[-1] +["clubB"]
>else:
>G = lines[-1] +["no"]
> finale.append(G)
> ###
> I just wonder if is appropriate to use a loops to check if is present the
> value on a list. Is it the right way? I can use a dictionary because I
> have many repeated names.
You mean you have people who are members in more than one club? You can
still use a dictionary if you make the value a list:
# untested code!
membership = {}
club = "club_of_people_who_are_not_in_any_club"
members = ["Erwin", "Kurt", "Groucho"]
for name in members:
# can be simplified with dict.setdefault() or collections.defaultdict
if name in membership:
membership[name].append(club)
else:
membership[name] = [club]
Put that in a loop over (club, members) pairs, and you'll end up with a dict
that maps name --> list_of_clubs.
Then iterate over the lines in the file:
with open("file.in") as source:
for line in source:
name = line.strip()
if name in membership:
print(name, *membership[name])
else:
print(name, "no")
>
> In the end I wan to have
>
>
> mary clubA clubB
> luke clubA
> luigi no
> Thanks in advance for any help
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Re: [Tutor] Help on best way to check resence of item inside list
On Tue, May 27, 2014 at 10:05:30AM +0200, jarod...@libero.it wrote:
[...]
> with open("file.in") as p:
> mit = []
You have lost the indentation, which makes this code incorrect.
But the rest of the code is too complicated.
> for i in p:
>lines =i.strip("\n").split("\t")
>if (lines[0] in clubA:
> G =lines[-1] +["clubA"]
>else:
>G = lines[-1] +["no"]
> mit.append(G)
>
> for i in mit:
>if i.strip("\n").split("\t")[0] in clubB:
> G =lines[-1] +["clubB"]
>else:
>G = lines[-1] +["no"]
> finale.append(G)
Look at the result you want to get:
> mary clubA clubB
> luke clubA
> luigi no
That suggests to me that the best data structure is a dict with sets:
{'mary': set(['clubA', 'clubB']),
'luke': set(['clubA']),
'luigi': set(),
}
Something like this should work:
names = {}
with open("file.in") as p:
# This assumes the data file is one name per line.
for line in p:
name = line.strip()
s = names.get(name, set()) # If name not in the names,
# return an empty set.
if name in clubA:
s.add("clubA")
if name in clubB:
s.add("clubB")
names[name] = s
print(names)
And I think that should work.
--
Steven
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Re: [Tutor] Help on best way to check resence of item inside list
"jarod...@libero.it" Wrote in message:
> Dear All
>
> clubA= ["mary","luke","amyr","marco","franco","lucia", "sally","genevra","
> electra"]
> clubB= ["mary","rebecca","jane","jessica","judit","sharon","lucia", "sally","
> Castiel","Sam"]
>
> I have a list of names that I would to annotate in function of presence in
> different clubs:
>
> my input files is a long file where I have this :
>
> mary
> luke
> luigi
> jane
> jessica
> rebecca
> luis
> à
>
> with open("file.in") as p:
> mit = []
> for i in p:
>lines =i.strip("\n").split("\t")
>if (lines[0] in clubA:
> G =lines[-1] +["clubA"]
>else:
>G = lines[-1] +["no"]
> mit.append(G)
>
>
> for i in mit:
>if i.strip("\n").split("\t")[0] in clubB:
> G =lines[-1] +["clubB"]
>else:
>G = lines[-1] +["no"]
> finale.append(G)
> ###
> I just wonder if is appropriate to use a loops to check if is present the
> value on a list. Is it the right way? I can use a dictionary because I have
> many repeated names.
>
> In the end I wan to have
>
>
> mary clubA clubB
> luke clubA
> luigi no
> Thanks in advance for any help
There are numerous errors in the above code. You should use
copy/paste, so we don't waste energy identifying errors that
don't even exist in your actual code. As it stands, it wouldn't
even compile.
But even if you fix the typos and indentation errors and
initialization errors, you still have logic errors if you want
the output you specify. First, the second loop doesn’t set the
lines variable at all, but just uses the value from the last
iteration of the first loop. Second, even if you untangle that,
luigi would end up with two 'no's, not one.
You don't say what list could have repeats. I don't see any in
your sample data. You also don't say how they should be treated.
For example, Are all seventeen mary's in clubA?
Now to your specific question. You aren't using the loops to
check the lists for a name. You're quite reasonably using
'in'.
You can accomplish your apparent goal much more reasonably by
using a single loop and more complex if elif and
else.
--
DaveA
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Re: [Tutor] Help on best way to check resence of item inside list
On 27/05/2014 09:05, jarod...@libero.it wrote:
Dear All
clubA= ["mary","luke","amyr","marco","franco","lucia", "sally","genevra","
electra"]
clubB= ["mary","rebecca","jane","jessica","judit","sharon","lucia", "sally","
Castiel","Sam"]
I have a list of names that I would to annotate in function of presence in
different clubs:
my input files is a long file where I have this :
mary
luke
luigi
jane
jessica
rebecca
luis
à
with open("file.in") as p:
mit = []
for i in p:
lines =i.strip("\n").split("\t")
if (lines[0] in clubA:
G =lines[-1] +["clubA"]
else:
G = lines[-1] +["no"]
mit.append(G)
for i in mit:
if i.strip("\n").split("\t")[0] in clubB:
G =lines[-1] +["clubB"]
else:
G = lines[-1] +["no"]
finale.append(G)
###
I just wonder if is appropriate to use a loops to check if is present the
value on a list. Is it the right way? I can use a dictionary because I have
many repeated names.
In the end I wan to have
mary clubA clubB
luke clubA
luigi no
Thanks in advance for any help
You can use the in keyword to check for an item in a list. However a
very quick glance at your code suggests that you could cut out the list
completely and do the same using the in keyword against your dict.
Better still I think the defaultdict is what you need here, I'll leave
you to look it up as I must dash :)
--
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.
Mark Lawrence
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[Tutor] Help on best way to check resence of item inside list
Dear All
clubA= ["mary","luke","amyr","marco","franco","lucia", "sally","genevra","
electra"]
clubB= ["mary","rebecca","jane","jessica","judit","sharon","lucia", "sally","
Castiel","Sam"]
I have a list of names that I would to annotate in function of presence in
different clubs:
my input files is a long file where I have this :
mary
luke
luigi
jane
jessica
rebecca
luis
à
with open("file.in") as p:
mit = []
for i in p:
lines =i.strip("\n").split("\t")
if (lines[0] in clubA:
G =lines[-1] +["clubA"]
else:
G = lines[-1] +["no"]
mit.append(G)
for i in mit:
if i.strip("\n").split("\t")[0] in clubB:
G =lines[-1] +["clubB"]
else:
G = lines[-1] +["no"]
finale.append(G)
###
I just wonder if is appropriate to use a loops to check if is present the
value on a list. Is it the right way? I can use a dictionary because I have
many repeated names.
In the end I wan to have
mary clubA clubB
luke clubA
luigi no
Thanks in advance for any help
___
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