Here are quite a few ways to add dictionaries. You can use Python3's dictionary unpacking feature: ndic = {**dic0, **dic1} Note that in the case of duplicates, values from later arguments are used. This is also the case for the other examples listed here.

How can I merge two Python dictionaries in a single expression? For dictionaries x and y, their shallowly-merged dictionary z takes values from y, replacing those from x. In Python 3.9.0 or greater (released 17 October 2020, PEP-584, discussed here): z = x | y In Python 3.5 or greater: z = {**x, **y} In Python 2, (or 3.4 or lower) write a function:

Aug 25, 2018 · How can I add values in different dictionaries with same keys together? 549 Is there any pythonic way to combine two dicts (adding values for keys that appear in both)?

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 updated with those key/value pairs: d.update(red=1, blue=2).

May 9, 2010 · Starting in Python 3.9, the operator | creates a new dictionary with the merged keys and values from two dictionaries: # d1 = { 'a': 1, 'b': 2 } # d2 = { 'b': 1, 'c': 3 } d3 = d2 | d1 # d3: {'b': 2, 'c': 3, 'a': 1} This: Creates a new dictionary d3 with the merged keys and values of d2 and d1. The values of d1 take priority when d2 and d1 share ...

Unless all keys are known to be strings, option 2 is an abuse of a Python 2 implementation detail (the fact that some builtins implemented in C bypassed the expected checks on keyword arguments). In Python 3 (and in PyPy), option 2 will fail with non-string keys. –

Apr 4, 2013 · dict can take an iterable of iterables, where each inner iterable has two items -- it then uses the first as the key and the second as the value for each item. Share Improve this answer

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) is nicer if you want to set multiple values at the same time, as long as the keys are strings (since kwargs are converted to strings).

I have a dictionary below, and I want to add to another dictionary with not necessarily distinct elements and merge its results. Is there any built-in function for this, or do I need to make my own...

I am new to python and I have a list of years and values for each year. What I want to do is check if the year already exists in a dictionary and if it does, append the value to that list of values for the specific key. So for instance, I have a list of years and have one value for each year: 2010 2 2009 4 1989 8 2009 7