There is a straight forward way to update an existing or empty directory from given a list of keys. In the first example below, we update dict only with keys, which were not already present. Notice that the key ‘a’ did get change and ‘z’ did not get deleted – they were left alone. The second example, basically initializes an empty dict object. Whereas, the third example creates a new dict object which did not exist before.
Tag Archives: Dictionary
Python: Find closest from given dictionary values
Objective: I have a dictionary, and a float value. I would like to sort the dictionary in such a way that, first key-value pair’s value is nearest (min absolute difference) to a given float value, and last would be the farthest (max absolute difference)
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| >>> chooseFrom | |
| {'1': 10.3438090737, '3': 7.73275047259, '2': 12.9046550095, '5': 10.3438090737, '4': 12.9046550095, '7': 7.88437303088, '6': 5.12169187146, '8': 0.0} | |
| >>> gh | |
| 7.73275047259 | |
| # reference : http://stackoverflow.com/a/12141207/799593 | |
| >>> test = sorted(chooseFrom, key=lambda x:abs(chooseFrom[x]-gh)) | |
| >>> test | |
| ['3', '7', '1', '5', '6', '2', '4', '8'] | |
| >>> for x in test: | |
| … print '{} : {} ==> {}'.format(x, chooseFrom[x], abs(gh-chooseFrom[x])) | |
| … | |
| 3 : 7.73275047259 ==> 0.0 | |
| 7 : 7.88437303088 ==> 0.15162255829 | |
| 1 : 10.3438090737 ==> 2.61105860111 | |
| 5 : 10.3438090737 ==> 2.61105860111 | |
| 6 : 5.12169187146 ==> 2.61105860113 | |
| 2 : 12.9046550095 ==> 5.17190453691 | |
| 4 : 12.9046550095 ==> 5.17190453691 | |
| 8 : 0.0 ==> 7.73275047259 |
Python: Compare Dictionaries
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| def compareDicts(d1, d2): | |
| differences = [] | |
| # present in d1 but not in d2 | |
| for key, value in ({k: d1[k] for k in set(d1) – set(d2)}).iteritems(): | |
| temp = list[[key, value], None] | |
| differences.append(temp) | |
| # present in d2 but not in d1 | |
| diff2 = {k: d2[k] for k in set(d2) – set(d1)} | |
| for key, value in (diff2).iteritems(): | |
| temp = [None, [key, value]] | |
| differences.append(temp) | |
| # updated from d1 to d2 | |
| updatedKeys = [item for item in list(set(d1.keys()) & set(d2.keys())) if d1.get(item) != d2.get(item)] | |
| for key in updatedKeys: | |
| temp = [[key, d1.get(key)],[key, d2.get(key)]] | |
| differences.append(temp) | |
| return differences | |
| pass |
Aarsh 