Jun 21, 2009 · @hegash the d[key]=val syntax as it is shorter and can handle any object as key (as long it is hashable), and only sets one value, whereas the .update(key1=val1, key2=val2) …

It sounds as if you are trying to setup a list of lists as each value in the dictionary. Your initial value for each drug in the dict is []. So assuming that you have list1 that you want to append to the …

Sep 23, 2019 · Add key: value pair to dictionary. The syntax dictionary[key] = message1 changes the existing value of dictionary[key] to message if the key is already in the dictionary, and …

(it is even slightly slower to make a list from one value to extend that). See What is the difference between Python's list methods append and extend?. Thus, what you show here to add a list …

This will create a new list object, if the key is not found in the dictionary. Note: Since the defaultdict will create a new list if the key is not found in the dictionary, this will have …

Oct 7, 2017 · In Python 2 you can avoid making a temporary copy of all the values by using the itervalues() dictionary method, which returns an iterator of the dictionary's keys: …

update() accepts either another dictionary object or an iterable of key/value pairs (as tuples or other iterables of length two). If keyword arguments are specified, the dictionary is then …

I got here looking for a way to add a key/value pair(s) as a group - in my case it was the output of a function call, so adding the pair using dictionary[key] = value would require me to know the …

Jan 24, 2017 · You can create your dictionary assigning a list to each key. d = {'word': [1], 'word1': [2]} and then use the following synthases to add any value to an existing key or to add a new …

Feb 2, 2018 · to create a new dictionary use: dict = dict() When you try to add something you use: += There is nothing to add. you have to first create the value. dict[some_variables_name1] = [{ …