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This is probably a noob question. For any dictionary 'd' in python is this always True:
dict( zip( d.keys(), d.values() ) ) == d
Are the keys and values returned in the same corresponding order ?
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Duplicate keys are not allowed. A dictionary maps each key to a corresponding value, so it doesn't make sense to map a particular key more than once.
Python's dictionary allows you to store key-value pairs, and then pass the dictionary a key to quickly retrieve its corresponding value. Specifically, you construct the dictionary by specifying one-way mappings from key-objects to value-objects.
An item has a key and a corresponding value that is expressed as a pair (key: value). While the values can be of any data type and can repeat, keys must be of immutable type (string, number or tuple with immutable elements) and must be unique.
To check if a key-value pair exists in a dictionary, i.e., if a dictionary has/contains a pair, use the in operator and the items() method. Specify a tuple (key, value) . Use not in to check if a pair does not exist in a dictionary.
Yes it's always true. Guaranteed by Python iff there are no intervening modifications to the ditionary.
Relevant spec: http://docs.python.org/library/stdtypes.html#dict.items
This is better generally, both because it protects against the dict going out of sync and uses negligible extra memory:
dict((k,v) for k,v in d.iteritems())
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