How to Store an Array in a Dictionary Using Python
I Am Currently Attempting to Modify a Series of Programs by Utilizing Dictionaries as Opposed to Arrays. I Have Columns of Raw Information in a File, Which Is...
I am currently attempting to modify a series of programs by utilizing dictionaries as opposed to arrays. I have columns of raw information in a file, which is then read into an ASCII csv file. I need to convert this file into a dictionary, so that it can be fed into another program.
I used a numpy.genfromtxt to pull out the information i need from the csv file, following this format:
a,b,c,d = np.genfromtxt("file",delimiter = ',', unpack = true)
this step works completely fine.
I then attempt to build a dictionary:
ouputDict = dict([a,a],[b,b],[c,c],[d,d])
As i understand it, this should make the key "a" in the dictionary a correspond to the array "a".
thus if:
a = [1,2,3,4]
then:
outputDict[a][0] = 1
However, when i attempt to create this dictionary i receive the following error:
TypeError: unhashable type: 'numpy.ndarray'
Why can't I construct an array in this fashion and what is the workaround, if any? Any help will be greatly appreciated!
2 Answers
You can do this even with using collections
Declare your dictionary as:
Dictionary = {}; // {} makes it a key, value pair dictionary
add your value for which you want an array as a key by declaring
Dictionary[a] = [1,2,3,4]; // [] makes it an array
So now your dictionary will look like
{a: [1,2,3,4]}
Which means for key a, you have an array and you can insert data in that which you can access like dictionary[a][0] which will give the value 1 and so on. :)
Btw.. If you look into examples of a dictionary, array and key value pairs, nested dictionary, your concept will get clearer.
Copied from my comment:
Correct dictionary formats:
{'a':a, 'b':b,...}, or
dict(a=a, b=b,...)
dict([('a', a), ('b', b),...])
The goal is to make the strings 'a','b',etc the keys, not the variable values.
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