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"To sort a dictionary" The concept of 'sort' applies only to a collection which has _order_ -- a sequence; a mapping (e.g. a dictionary) has NO order, thus it cannot be sorted. Still, its keys can be extracted as a list, which can then be sorted. The example functions return the values in order of sorted key, which just happens to be the single most frequent actual need corresponding to user questions such as "how do I sort a dictionary":-) The implementation choices are interesting. Since we are sorting key-value pairs by the key field, then returning the list of value fields, it seems clearest (conceptually simplest) to architect the solution as in the first example: .items, .sort, then a list comprehension to pick the value fields.

However (at least on my machine) this turns out not to be fastest: extracting just the keys, sorting them, then accessing the dictionary for each key in the resulting list comprehension, as in the second example, appears to be speedier. How to sort Python dictionary. In Python how do I sort a list of dictionaries by values of the dictionary. Python sorting list of dictionaries by multiple keys. Sort dictionary - Python answers. How do I sort these? - Python answers. Sort a dictionary by keys in specific order - Python answers. Sort dictionary by values (complex)! - Python answers. Python — Basics of Python Dictionary: Looping & Sorting « Useful Stuff.

Here some bits of info about python dictionaries & looping through them. Extra special beginner stuff. What is a dictionary? A python dictionary is an extremely useful data storage construct for storing and retreiving key:value pairs. Many languages implement simple arrays (lists in python) that are keyed by a integer. A dictionary is a little more advanced in that the keys can be many other things than integers. Will I remember that my_list[3] is my phone number?

Major differences vs lists - Keys are any hashable object (say strings for simplicity) - Are NOT ordered (a list is by definition ordered) One way I like to think about them are as little variable containers. In fact, variables are very much related to dictionaries! Watch and see: Looping through dictionaries Now, if you did a little experimenting, you would see that if you loop through a dictionary you loop through its keys.

Note that this is the equivalent of looping through “my_dict.keys()” What about getting the values? Conclusion. Mark Gregory Turansky » HOWTO: Sort a Python Dictionary/Map. I use Python all the time for quick little scripting tasks. There’s nothing better to slice and dice a file, so I use Python for a lot of reporting tasks. That usually involves building some kind of data structure in my script that I’m slicing and dicing from files. In my work, I have a LOT of units of work processing in parallel on a grid. I have GUIDs tagging each unit of work, and that GUID is the perfect key for a Map/Dictionary data structure. There are times, though, that I want to get the values of the Map and sort by some value in the data itself. The is important if I want to sort my results by elapsed time or some other interesting metric.

Here’s how you sort a Python Dictionary by some arbitrary value within the data structure: Here is the output: This entry was posted on May 11, 2009, 3:31 pm and is filed under HOW TO, Python. You can follow any responses to this entry through RSS 2.0. You can leave a response, or trackback from your own site. How to sort Python dict (dictionary) »Autarchy of the Private Cave.