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I have the key of a python dictionary and I want to get the corresponding index in the dictionary. Suppose I have the following dictionary,
d = { 'a': 10, 'b': 20, 'c': 30} Is there a combination of python functions so that I can get the index value of 1, given the key value 'b'?
d.??('b') I know it can be achieved with a loop or lambda (with a loop embedded). Just thought there should be a more straightforward way.
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The Python Dictionary object provides a key:value indexing facility. Note that dictionaries are unordered - since the values in the dictionary are indexed by keys, they are not held in any particular order, unlike a list, where each item can be located by its position in the list.
In dictionary, keys are unordered.
Dictionaries are sometimes found in other languages as “associative memories” or “associative arrays”. Unlike sequences, which are indexed by a range of numbers, dictionaries are indexed by keys, which can be any immutable type; strings and numbers can always be keys.
Use OrderedDicts: http://docs.python.org/2/library/collections.html#collections.OrderedDict
>>> x = OrderedDict((("a", "1"), ("c", '3'), ("b", "2"))) >>> x["d"] = 4 >>> x.keys().index("d") 3 >>> x.keys().index("c") 1 For those using Python 3
>>> list(x.keys()).index("c") 1 If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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