I am new to the whole python thing. I have a question and will try to keep it short.
I am trying to write a program where I have a group of items as below.
product_lookup = {"C1557E" : "FM51", "C1557E" : "JBC4343" "C1565ECA/2" : "FM349",
"C1568E" : "FM133", "C1578E" : "FM154"}
Now I have a enquiry (list of values) as below that I want to cross referance with the dictionary
enquiry_lookup = ["FM51", "FM133", "FM154", "GRE4534"]
Then I" want this displayed as
result ["FM51" : "C1557E", "FM133" : "C1568E", "FM154" : "C1578E", "GRE4534" : "NOT AVAILABLE"]
Firstly, is it possible?
I am stick... HELP PLEASE :)
Only just started and after working on a few things I am getting the feeling it might not be possible??
Please point me in the right direction.
Thanks a stack
G
This might give you a clue:
>>> dict = {"a" : "b", "c" : "d"}
>>>
>>> for k,v in dict.iteritems():
... print k
... print v
...
a
b
c
d
By using iteritems(), we iterate over all key,value pairs in our dictionary. So you can inspect the value to see if it is the value you are looking for, if so you can place the key and the value in your result dictionary.
But, if you are interested in a set of items, and those items are the values instead of the keys of your dictionary, are you sure your dictionary is not backwards? By which I mean, could your dictionary instead be
product_lookup = {"FM51" : "C1557E", etc}
then when you have
enquiry_lookup = ["FM51", etc
you can just see if product_lookup["FM51"] exists? This could be more efficient/easier to write.
Related
I'm quite new in python coding and I can´t solve the following problem:
I have a list with trackingpoints for different animals(ID,date,time,lat,lon) given in strings:
aList = [[id,date,time,lat,lon],
[id2,date,time,lat,lon],
[...]]
The txt file is very big and the IDs(a unique animal) is occuring multiple times:
i.e:
aList = [['25','20-05-13','15:16:17','34.89932','24.09421'],
['24','20-05-13','15:16:18','35.89932','23.09421],
['25','20-05-13','15:18:15','34.89932','24.13421'],
[...]]
What I'm trying to do is order the ID's in dictionaries so each unique ID will be the key and all the dates, times, latitudes and longitudes will be the values. Then I would like to write each individual ID to a new txt file so all the values for a specific ID are in one txt file. The output should look like this:
{'25':['20-05-13','15:16:17','34.89932','24.09421'],
['20-05-13','15:18:15','34.89932','24.13421'],
[...],
'24':['20-05-13','15:16:18','35.89932','23.09421'],
[...]
}
I have tried the following (and a lot of other solutions which didn't work):
items = {}
for line in aList:
key,value = lines[0],lines[1:]
items[key] = value
Which results in a key with the last value in the list forthat particular key :
{'25':['20-05-13','15:18:15','34.89932','24.13421'],
'24':['20-05-13','15:16:18','35.89932','23.09421']}
How can I loop through my list and assign the same IDs to the same key and all the corresponding values?
Is there any simple solution to this? Other "easier to implement" solutions are welcome!
I hope it makes sense :)
Try adding all the lists that match to the same ID as list of lists:
aList = [['25','20-05-13','15:16:17','34.89932','24.09421'],
['24','20-05-13','15:16:18','35.89932','23.09421'],
['25','20-05-13','15:18:15','34.89932','24.13421'],
]
items = {}
for line in aList:
key,value = line[0],line[1:]
if key in items:
items[key].append(value)
else:
items[key] = [value]
print items
OUTPUT:
{'24': [['20-05-13', '15:16:18', '35.89932', '23.09421']], '25': [['20-05-13', '15:16:17', '34.89932', '24.09421'], ['20-05-13', '15:18:15', '34.89932', '24.13421']]}
I have a query sequence that I blasted online using NCBIWWW.qblast. In my xml blast file result I obtained for a query sequence a list of hit (i.e: gi|). Each hit or gi| have multiple hsp. I made a dictionary my_dict1 where I placed gi| as key and I appended the bit score as value. So multiple values for each key.
my_dict1 = {
gi|1002819492|: [437.702, 384.47, 380.86, 380.86, 362.83],
gi|675820360| : [2617.97, 2614.37, 122.112],
gi|953764029| : [414.258, 318.66, 122.112, 86.158],
gi|675820410| : [450.653, 388.08, 386.27] }
Then I looked for max value in each key using:
for key, value in my_dict1.items():
max_value = max(value)
And made a second dictionary my_dict2:
my_dict2 = {
gi|1002819492|: 437.702,
gi|675820360| : 2617.97,
gi|953764029| : 414.258,
gi|675820410| : 450.653 }
I want to compare both dictionary. So I can extract the hsp with the highest score bits. I am also including other parameters like query coverage and identity percentage (Not shown here). The finality is to get the best gi| with the highest bit scores, coverage and identity percentage.
I tried many things to compare both dictionary like this :
First code :
matches[]
if my_dict1.keys() not in my_dict2.keys():
matches[hit_id] = bit_score
else:
matches = matches[hit_id], bit_score
Second code:
if hit_id not in matches.keys():
matches[hit_id]= bit_score
else:
matches = matches[hit_id], bit_score
Third code:
intersection = set(set(my_dict1.items()) & set(my_dict2.items()))
Howerver I always end up with 2 types of errors:
1 ) TypeError: list indices must be integers, not unicode
2 ) ... float not iterable...
Please I need some help and guidance. Thank you very much in advance for your time. Best regards.
It's not clear what you're trying to do. What is hit_id? What is bit_score? It looks like your second dict is always going to have the same keys as your first if you're creating it by pulling the max value for each key of the first dict.
You say you're trying to compare them, but don't really state what you're actually trying to do. Find those with values under a certain max? Find those with the highest max?
Your first code doesn't work because I'm assuming you're trying to use a dict key value as an index to matches, which you define as a list. That's probably where your first error is coming from, though you haven't given the lines where the error is actually occurring.
See in-code comments below:
# First off, this needs to be a dict.
matches{}
# This will never happen if you've created these dicts as you stated.
if my_dict1.keys() not in my_dict2.keys():
matches[hit_id] = bit_score # Not clear what bit_score is?
else:
# Also not sure what you're trying to do here. This will assign a tuple
# to matches with whatever the value of matches[hit_id] is and bit_score.
matches = matches[hit_id], bit_score
Regardless, we really need more information and the full code to figure out your actual goal and what's going wrong.
I have a python dictionary like :
pydict = {"group1":[{"name":"john","count":1},{"name":"johny","count":2}],
"group2":[{"name":"raj","count":1},{"name":"johny","count":4}],
"group3":[{"name":"ram","count":1},{"name":"raj","count":4}]
}
I want to iterate through pydict and i want to maintain a table like below:
Name group1 group2 group3
johny true true
raj true true
I tried using python sets so the each keys elements in pydict can be assigned to sets and finally do intersection but it is not helping.
Please suggest me a fastest way to do this.
A really naive implementation of this would be to just make another dict based on names:
from collections import defaultdict
names = defaultdict(set)
for group in sorted(pydict.keys()):
for person in pydict[group]:
names[person["name"]].add(group)
for key, val in names.iteritems():
print key, ":", list(val)
Output
johny : ['group1', 'group2']
john : ['group1']
raj : ['group3', 'group2']
ram : ['group3']
As what mentioned in the Title, if both of them serve for the same purpose?
Most of the time i will chose to use list, and i don't know when is a better time to use set.add() function.
I try both of them and give me the exact same result...
Personally feel list is better. What do you guys think?
a = set()
a.add('a1')
a.add('a2')
a.add('a3')
for ele in a:
print ele
b = []
b.append('a1')
b.append('a2')
b.append('a3')
for ele in b:
print ele
Please advise...
In terms of general data structures, a set structure tends to allow only one element of each value whereas a list may have more than one of each.
In other words, the pseudo-code set.add(7) executed twice results in the set containing the single element 7 (or an error if it considers adding the same element twice to be invalid).
Using a list instead of a set would result in two elements, both being 7.
For Python specifically, adding duplicates to a set is not an error but it still plainly only allows one of each:
>>> s = set()
>>> s.add(1)
>>> s.add(1)
>>> s.add(2)
>>> s
set([1, 2])
The list on the other hand allows multiples:
>>> l = list()
>>> l.append(1)
>>> l.append(1)
>>> l.append(2)
>>> l
[1, 1, 2]
The reason why you didn't see a difference is simply because you added three unique items to the list and set. In that context, they act the same. Behaviour only diverges when you add duplicate items.
I'm trying to use numbers as my dict key. Is there anyway to initiate the dictionary using dict() method?
This works
mydict = { '100':'hundred', '200':'two hundred'}
This doesn't work?
mydict = dict( 100='hundred' )
The error says 'keyword can't be an expression' and I couldn't find any solution.
Thank you.
I can't understand your question exactly, but you mentioned to use number as dict key right? you just directly initiate it using integer instead string like this..
a = {1:'one',100:'hundered'}
print a
{1: 'one', 100: 'hundrered'}
No, it mist be a valid python identifier, so it cannot start with a number.
You can read where i found it at here in the part about dict
https://docs.python.org/2/library/stdtypes.html#typesmapping
Like the comment above says you can use an int, since dictionaries just hash the string and you get an int anyways, in the case of an int it just hashes to itself. But it doesnt work with dict ()
On that page it shows you can do
mydict = dict (zip ([1], ["one"]))
Which is kinda ugly imo, but seems to get the job done
To use the dict method you need to feed it a list or tuple of lists or tuples.
>>> dict([(100, 'hundred'), (200, 'two hundred')])
{200: 'two hundred', 100: 'hundred'}