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d = dict((k, v) for k, v in d.iteritems() if v > 0) In Python 2.7 and up, there's nicer syntax for this: d = {k: v for k, v in d.items() if v > 0} Note that this is not strictly a filter because it does create a new dictionary. edited May 18, 2015 at 23:40.
You can use the dictionary constructor and implicit expansion to reconstruct a dictionary. Moreover, interestingly, this method can be used to control the positional order during dictionary construction (post Python 3.6). In fact, insertion order is guaranteed for Python 3.7 and above!
to test if "one" is among the values of your dictionary. In Python 2, it's more efficient to use. "one" in d.itervalues() instead. Note that this triggers a linear scan through the values of the dictionary, short-circuiting as soon as it is found, so this is a lot less efficient than checking whether a key is present.
@OrsirisdeJong dict.keys(), etc are dictionary view objects and have been so in all Python 3 releases, not just since 3.6. Don’t turn those into a list, use next((k for k, v in dict.items() if v == search_age), None) to find a match.
There are two ways to add one dictionary to another: Update (modifies orig in place) orig.update(extra) # Python 2.7+. orig |= extra # Python 3.9+. Merge (creates a new dictionary) # Python 2.7+. dest = collections.ChainMap(orig, extra) dest = {k: v for d in (orig, extra) for (k, v) in d.items()} # Python 3.
Python - create dictionary from list of dictionaries. 20. Creating a dictionary with list of lists in ...
Python 2. For Python 2.2+ releases, the same code will work. However, it is better to use iteritems() dictionary method instead of items() for performance. Notes. This answer is based on the comments on Climbs_lika_Spyder's answer. The used code was tested on Python 3.5.2 and Python 2.7.10 .
When you iterate through dictionaries using the for .. in .. -syntax, it always iterates over the keys (the values are accessible using dictionary[key]). To iterate over key-value pairs, use the following: for k,v in dict.iteritems() in Python 2. for k,v in dict.items() in Python 3.
Unless you really want to keep the dictionary, I think the best solution is to use the csv Python module to read the file. Then, you get rows of data and you can change member_phone or whatever you want ; finally, you can use the csv module again to save the file in the same format as you opened it.
Few people appear, despite the many answers to this question, to have pointed out that dictionaries are un-ordered mappings, and so (until the blessing of insertion order with Python 3.7) the idea of the "first" entry in a dictionary literally made no sense.