If you were to solve it with a third-party package, like jsonpath-rwthe solution would be as simple as constructing the path by joining the keys with a dot and parsing the dictionary:.
You can chain together dict. Except, let the last. If any of the keys to be traversed are missing, a empty dict is returned and the following. I like the following approach that makes use of functools.
It generalizes nicely to other indexable sequences such as lists and tuples. Sign up to join this community.
The best answers are voted up and rise to the top. Home Questions Tags Users Unanswered. Get value from dictionary given a list of nested keys Ask Question. Asked 3 years, 1 month ago. Active 8 months ago. Viewed 39k times. Could this solution be improved?
Python | Extract key-value of dictionary in variables
Martin Burch Martin Burch 1 1 gold badge 3 3 silver badges 9 9 bronze badges. Active Oldest Votes. ChatterOne ChatterOne 2, 7 7 silver badges 16 16 bronze badges. Adam Porad Adam Porad 3 3 bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook.Example Python program that converts a pandas DataFrame into a Python dictionary.
Create a DataFrame. Convert the DataFrame to Series. Contents of the DataFrame:. DataFrame as a dictionary:. Example Python program that converts a pandas DataFrame into a. Python dictionary in list mode. Create DataFrame. Convert the DataFrame to dictionary. Daily temperature from DataFrame:. DataFrame as a dictionary List orientation :.
Toggle navigation Pythontic. The output can be specified of various orientations using the parameter orient. In dictionary orientation, for each column of the DataFrame the column value is listed against the row label in a dictionary. All these dictionaries are wrapped in another dictionarywhich is indexed using column labels. Dictionary orientation is the default orientation for the conversion output. In list orientation, each column is made a list and the lists are added to a dictionary against the column labels.
In series orientation, each column is made a pandas Seriesand the series instances are indexed against the row labels in the returned dictionary object. In split orientation, each row is made a list and they are wrapped in another list and indexed with the key "data" in the returned dictionary object. The row labels are stored in a list against the key "index". The columns labels are stored in a list against the key "columns".
In records orientation, each column is made a dictionary where the column elements are stored against the column name.
All the dictionaries are returned as a list. In index orientation, each column is made a dictionary where the column elements are stored against the column name. All the dictionaries are returned in a dictionarywhich is indexed by the row labels.Post a Comment. Total Pageviews. You want to extract from a larger dictionary only that subset of it that corresponds to a certain set of keys.
In Python, I use dictionaries for many purposesdatabase rows, primary and compound keys, variable namespaces for template parsing, and so on. So, I often need to create a dictionary that is based on another, larger dictionary, but only contains the subset of the larger dictionary corresponding to some set of keys. In most use cases, the larger dictionary must remain intact after the extraction; sometimes, however, I need to remove from the larger dictionary the subset that I'm extracting.
This recipe's solution shows both possibilities. The only difference is that you use method get when you want to avoid affecting the dictionary that you are getting data from, method pop when you want to remove the items you're getting. If some item k of somekeys is not in fact a key in somedictthis recipe's functions put k as a key in the result anyway, with a default value which I pass as an optional argument to either function, with a default value of None.
So, the result is not necessarily a subset of somedict. This behavior is the one I've found most useful in my applications.
You might prefer to get an exception for "missing keys"that would help alert you to a bug in your program, in cases in which you know all k s in somekeys should definitely also be keys in somedict.
Remember, "errors should never pass silently. Unless explicitly silenced," to quote The Zen of Pythonby Tim Peters enter the statement import this at an interactive Python prompt to read or re-read this delightful summary of Python's design principles. So, if a missing key is an error, from the point of view of your application, then you do want to get an exception that alerts you to that error at once, if it ever occurs. If this is what you want, you can get it with minor modifications to this recipe's functions:.
As you can see, these strict variants are even simpler than the originalsa good indication that Python likes to raise exceptions when unexpected behavior occurs!
Alternatively, you might prefer missing keys to be simply omitted from the result. This, too, requires just minor modifications:. In Python 2. Just change the syntax of the calls to dictfrom dict [.
However, these variants would not work in Python 2. No comments:. Newer Post Older Post Home. Subscribe to: Post Comments Atom.Sometimes, while working with dictionaries, we can face a problem in which we may have just a singleton dictionary, i.
This kind of problem can come in day-day programming. Method 1 : Using items This problem can be solved using the items function which does the task of extracting a key-value pair and using the 0th index gives us the first key-value pair.
Works only in Python2. It uses iterators to perform this task. The next is used to fetch the pairs till dictionary is exhausted. It works with Python3. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute. See your article appearing on the GeeksforGeeks main page and help other Geeks. Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below. Writing code in comment? Please use ide. Python code to demonstrate working of.
Extracting key-value of dictionary in variables. Python3 code to demonstrate working of. Recommended Posts: Python Extract filtered Dictionary Values Python Extract specific keys from dictionary Ways to extract all dictionary values Python Python Convert nested dictionary into flattened dictionary Python Convert flattened dictionary into nested dictionary Python Convert string dictionary to dictionary Python Dictionary initialization with common dictionary Regular Dictionary vs Ordered Dictionary in Python Python Pretty Print a dictionary with dictionary value numpy.
Check out this Author's contributed articles. Load Comments.Till now, we have seen the ways to creating dictionary in multiple ways and different operations on the key and values in dictionary.
Note that the restriction with keys in Python dictionary is only immutable data types can be used as keys, which means we cannot use a dictionary of list as a key. But the same can be done very wisely with values in dictionary. Iterate the list and keep appending the elements till given range using setdefault method. Note that the same thing can also be done with simple dictionary but using defaultdict is more efficient for such cases.
Note that there are only two key:value pairs in output dictionary but the input list contains three tuples.
The first element i. Method 6: Using Json. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute. See your article appearing on the GeeksforGeeks main page and help other Geeks. Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below. Writing code in comment? Please use ide. Creating a dictionary. Creating an empty dictionary. Adding this list as sublist in myDict.
Creating an empty dict. Iterating the elements in list. Creating a dictionary of lists. Importing defaultdict. Added by Paras Jain everythingispossible. Recommended Posts: Create pandas dataframe from lists using dictionary How to create a Dictionary in Python Python Convert two lists into a dictionary Python Concatenate dictionary value lists Python Iterate through value lists dictionary Python Create a dictionary using list with none values Python program to create a dictionary from a string Python Initializing dictionary with empty lists Python - Cumulative product of dictionary value lists Python Ways to Copy Dictionary Python Ways to remove a key from dictionary Python Convert list of tuples to dictionary value lists Python Split dictionary of lists to list of dictionaries Python Ways to change keys in dictionary Python Ways to invert mapping of dictionary.
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Python : How to convert a list to dictionary ?
Improved By : everythingispossible. Load Comments.In this article we will discuss different ways to convert a single or multiple lists to dictionary in Python. Now we want to create a dictionary with all elements in this list as keys. For each key value will be same i.
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It returns a dictionary with items in list as keys. All dictionary items will have same value, that was passed in fromkeys. If no default value was passed in fromKeys then default value for keys in dictionary will be None.
Zip accepts a number of iterable objects and returns a list of tuples. Each entry in tuple contains an element from each iterable object.
We have passed two lists objects in zipso it will return a list of tuples, where each tuple contains an entry from both the lists. Then we created a dictionary object from this list of tuples. Entries in first column will become the key and entries in second column will the values in the new dictionary. Contents of dictionary will be. Top 5 online Python courses for beginners in Your email address will not be published.
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Python : How to convert a list to dictionary? Varun June 30, Python : How to convert a list to dictionary? Following conversions from list to dictionary will be covered here, Convert a List to Dictionary with same values Convert List items as keys in dictionary with enumerated value Convert two lists to dictionary Convert a list of tuples to dictionary Convert a List to Dictionary with same values Suppose we have a list of strings i.
List of strings. Converting a list to dictionary with list elements as keys in dictionary. All keys will have same value.
Converting a list to dictionary with list elements as values in dictionary. List of ints.In this article we will discuss different methods to generate a list of all files in directory tree. We need to call this recursively for sub directories to create a complete list of files in given directory tree i.
Iterate over the directory tree and generate a list of all the files at given path. Your email address will not be published. This site uses Akismet to reduce spam. Learn how your comment data is processed. Creating a list of files in directory and sub directories using os. For the given path, get the List of all files in the directory tree.
Iterate over all the entries. Create full path. If entry is a directory then get the list of files in this directory. Get the list of all files in directory tree at given path. Print the files. Python : How to check if a directory is empty? How to create a Directory in python? Python: How to create a zip archive from multiple files or Directory Python : How to remove files by matching pattern wildcards certain extensions only?
Python : How to move files and Directories? How to change current working directory in python? Python : How to delete a directory recursively using shutil. Thanks varnum, worked perfectly on my old Mavericks operating sys. Leave a Reply Cancel reply Your email address will not be published.