Python Program to Re-assign a dictionary based on path relation

Python Program to Re-assign a dictionary based on path relation

Re-assigning a dictionary based on path relations can be a bit tricky, especially if the dictionary represents a nested structure. In this tutorial, we'll take a simple example of re-assigning a value in a nested dictionary based on a given "path".

Scenario: Let's say you have a nested dictionary that represents a file system. You want to modify the value of an item based on its "path".

Example Dictionary:

filesystem = { 'root': { 'folder1': { 'file1.txt': 'content', 'file2.txt': 'content' }, 'folder2': { 'folder3': { 'file3.txt': 'content' } } } }

You want to modify the value of 'file1.txt' which is located at the path 'root/folder1/file1.txt'.

Steps:

  1. Split the given path into its components.
  2. Traverse the dictionary using the path components.
  3. Re-assign the final component with the new value.

Python Code:

def reassign_dictionary_value(d, path, new_value): """ Re-assign a value in a nested dictionary based on a given path. :param d: The dictionary. :param path: Path to the item in the format 'key1/key2/key3/...'. :param new_value: The new value to set. """ keys = path.split('/') # Traverse all keys except the last one for key in keys[:-1]: d = d[key] # Re-assign the value of the last key in the path d[keys[-1]] = new_value # Example usage: filesystem = { 'root': { 'folder1': { 'file1.txt': 'content', 'file2.txt': 'content' }, 'folder2': { 'folder3': { 'file3.txt': 'content' } } } } path = 'root/folder1/file1.txt' new_content = 'new content' reassign_dictionary_value(filesystem, path, new_content) print(filesystem['root']['folder1']['file1.txt']) # This should display 'new content'

Explanation:

  • We've defined a function reassign_dictionary_value that takes in a dictionary d, a path path, and a new value new_value.
  • The path is split into its components using the split method.
  • We then traverse the dictionary using the keys derived from the path.
  • Finally, we re-assign the value of the last key in the path with the provided new value.

This approach will help you change values in nested dictionaries based on a given path. Adjustments can be made to handle more complex scenarios or path formats if needed.

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