Appending values to dictionary in Python

user_117700 0
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I have a dictionary to which I want to append to each drug, a list of numbers. Like this:

append(0), append(1234), append(123), etc.

def make_drug_dictionary(data):
    drug_dictionary={'MORPHINE':[],
                     'OXYCODONE':[],
                     'OXYMORPHONE':[],
                     'METHADONE':[],
                     'BUPRENORPHINE':[],
                     'HYDROMORPHONE':[],
                     'CODEINE':[],
                     'HYDROCODONE':[]}
    prev = None
    for row in data:
        if prev is None or prev==row[11]:
            drug_dictionary.append[row[11][]
    return drug_dictionary

I later want to be able to access the entirr set of entries in, for example, 'MORPHINE'.

  1. How do I append a number into the drug_dictionary?
  2. How do I later traverse through each entry?
dictionary python
8 Answers

If you want to append to the lists of each key inside a dictionary, you can append new values to them using + operator (tested in Python 3.7):

mydict = {'a':[], 'b':[]}
print(mydict)
mydict['a'] += [1,3]
mydict['b'] += [4,6]
print(mydict)
mydict['a'] += [2,8]
print(mydict)

and the output:

{'a': [], 'b': []}
{'a': [1, 3], 'b': [4, 6]}
{'a': [1, 3, 2, 8], 'b': [4, 6]}

mydict['a'].extend([1,3]) will do the job same as + without creating a new list (efficient way).

user_9369660

You can use the update() method as well

d = {"a": 2}
d.update{"b": 4}
print(d) # {"a": 2, "b": 4}
user_114307260
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