Cara menggunakan split nested dictionary python

Question

Last update on August 19 2022 21:51:49 (UTC/GMT +8 hours)

Python dictionary: Exercise-27 with Solution

Write a Python program to convert a list into a nested dictionary of keys.

Table of Contents Show

Python dictionary: Exercise-27 with Solution
Visualize Python code execution:
Python: Tips of the Day
A Simple Nested List
A Simple Nested Dictionary
A More Complex Example
Operations on Nested Lists and Dictionaries
Can list be nested in dictionary Python?
How do you create a nested list in a dictionary?
How do I convert a list to a dictionary in Python?
How do you flatten a dictionary with nested lists and dictionaries in Python?

Table of Contents

Python dictionary: Exercise-27 with Solution
Visualize Python code execution:
Python: Tips of the Day
A Simple Nested List
A Simple Nested Dictionary
A More Complex Example
Operations on Nested Lists and Dictionaries
Can list be nested in dictionary Python?
How do you create a nested list in a dictionary?
How do I convert a list to a dictionary in Python?
How do you flatten a dictionary with nested lists and dictionaries in Python?

Sample Solution:-

Python Code:

num_list = [1, 2, 3, 4]
new_dict = current = {}
for name in num_list:
    current[name] = {}
    current = current[name]
print(new_dict)

Sample Output:

{1: {2: {3: {4: {}}}}}

Visualize Python code execution:

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Python Code Editor:

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Previous: Write a Python program to count the values associated with key in a dictionary.
Next: Write a Python program to sort a list alphabetically in a dictionary.

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Python: Tips of the Day

Difference In Sets:

To retrieve the difference between two sets:

a = {1,2,3}
b = {3,4,5}w
c = a.difference(b)

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Today we’ll be talking about the nested list and dictionary. Nested lists and dictionaries are often used to better structure your data. Theoretically there are no limits to the depth of nesting and you can have a list inside another list, which is inside yet another list, which itself also is inside another list, etc. Confusing? Because it is or rather it may quickly become if you stop using common sense when structuring your code using nested lists and dictionaries. We’re going to see a more complex example in a moment. But let’s start simple.

A Simple Nested List
A Simple Nested Dictionary
A More Complex Example
Operations on Nested Lists and Dictionaries

A Simple Nested List

Lists and dictionaries may be nested. Here’s a simple example of a nested list. Watch how indices are used.

teams = [["Ben", "Bob", "Mike"], ["Ann", "Sue"], ["Ron", "Sarah", "Edwin"]]
print(f"In {teams[0][0]}'s team {teams[0][2]} is the oldest.")

So, there are two indices, one for each level of nesting. The first index is 0, so it refers to the first element in the outer list, which is the inner list [“Ben”, “Bob”, “Mike”]. The second index refers to the appropriate element inside this list, so the element teams[0][0] is “Ben” and teams[0][2] is “Mike”.

The output is:

In Ben's team Mike is the oldest.

A Simple Nested Dictionary

Now a simple nested dictionary:

worker = {"name": {"first": "Jane", "last": "Jackson"},
          "address": {"country": "USA", "city": "Denver"},
          "age": 57}

print(f'Mrs. {worker["name"]["last"]}, aged {worker["age"]}, lives in {worker["address"]["city"]}.')

Now there are two keys, again one for each level of nesting. The output is:

Mrs. Jackson, aged 57, lives in Denver.

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A More Complex Example

And now a more complex example: A dictionary that contains simple elements, nested lists and nested dictionaries. Such complicated structures are seldom used, but it’s just to illustrate how the particular elements can be retrieved:

animals = {"species": {"english": "wolf", "latin": "Canis lupus"},
           "class": "mammals",
           "habitats": ["forests", "tundras", "grasslands"],
           "dimensions": {"body": {"length": 150, "height": 80},
                          "tail": {"length": 40}}}

print("Latin name: " + animals["species"]["latin"])
print("Class: " + animals["class"])
print("Main habitat: " + animals["habitats"][0])
print("Body height: " + str(animals["dimensions"]["body"]["height"]))

The output is:

Latin name: Canis lupus
Class: mammals
Main habitat: forests
Body height: 80

Operations on Nested Lists and Dictionaries

You can perform operations on particular nested lists and dictionaries:

animals = {"species": {"english": "wolf", "latin": "Canis lupus"},
           "class": "mammals",
           "habitats": ["forests", "tundras", "grasslands"],
           "dimensions": {"body": {"length": 150, "height": 80},
                          "tail": {"length": 40}}}

animals["species"]["french"] = "loup"  # add element to dictionary
animals["habitats"].append("deserts")  # append to list
animals["dimensions"]["tail"]["length"] *= 1.5 # augmented assignment

print("Names: " + str(animals["species"]))
print("Habitats: " + str(animals["habitats"]))
print("Tail length: " + str(animals["dimensions"]["tail"]["length"]))

The output is:

Names: {'english': 'wolf', 'latin': 'Canis lupus', 'french': 'loup'}
Habitats: ['forests', 'tundras', 'grasslands', 'deserts']
Tail length: 60.0

Naturally you should avoid overcomplicating things and usually you won’t use lists or dictionaries with so many levels of nesting on a regular basis. I hope, though, that you will be familiar with them if you come across them in code.

Here’s the video version:

Can list be nested in dictionary Python?

You can have dicts inside of a list. The only catch is that dictionary keys have to be immutable, so you can't have dicts or lists as keys.

How do you create a nested list in a dictionary?

To create a nested dictionary, simply pass dictionary key:value pair as keyword arguments to dict() Constructor. You can use dict() function along with the zip() function, to combine separate lists of keys and values obtained dynamically at runtime.

How do I convert a list to a dictionary in Python?

Since python dictionary is unordered, the output can be in any order. To convert a list to dictionary, we can use list comprehension and make a key:value pair of consecutive elements. Finally, typecase the list to dict type.

How do you flatten a dictionary with nested lists and dictionaries in Python?

Basically the same way you would flatten a nested list, you just have to do the extra work for iterating the dict by key/value, creating new keys for your new dictionary and creating the dictionary at final step. For Python >= 3.3, change the import to from collections.

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