Reference library

Dictionaries & sets

Key–value maps, uniqueness, counting, grouping, and fast lookups.

6 matches

Find All Leaf Paths in a Nested Dict in Python

Recursively traverse a nested dictionary and yield every leaf path as a list of keys, including paths to empty dictionaries.

dictionary recursion nested-data

Python

def find_leaf_paths(data, path=None):
    if path is None:
        path = []
    
    if not isinstance(data, dict) or not data:
        yield path
        return
    
    for key, value in data.items():
        yield from find_leaf_paths(value, path + [key])

if __name__ == "__main__":
    nested = {
        "a": 1,
…

13 0 Open

Dictionaries & sets easy

Flatten a Nested Dict to Dot Notation Keys in Python

Recursively flatten a nested dictionary into a flat dictionary with dot-separated keys using a small recursive function.

dict flatten recursion

Python

def flatten_dict(nested, parent_key='', sep='.'):
    items = {}
    for key, value in nested.items():
        new_key = f"{parent_key}{sep}{key}" if parent_key else key
        if isinstance(value, dict):
            items.update(flatten_dict(value, new_key, sep))
        else:
            items[new_key] = value
    …

11 0 Open

Dictionaries & sets medium

How to Deep Merge Nested Dicts Recursively in Python

Recursively merge two Python dictionaries, with overlay values taking precedence while preserving nested structures.

dict-merge recursion nested-dicts

Python

def deep_merge(base, overlay):
    """
    Recursively merge two dictionaries.
    Values in 'overlay' take precedence over 'base'.
    """
    result = base.copy()
    
    for key, value in overlay.items():
        if key in result and isinstance(result[key], dict) and isinstance(value, dict):
            result[key…

14 0 Open

Dictionaries & sets medium

How to Recursively Remove None Values from Nested Dictionaries in Python

Recursively removes all None values from nested dictionaries and lists while preserving non-None data.

dictionaries recursion data-cleaning

Python

def prune_none(obj):
    if isinstance(obj, dict):
        return {
            k: prune_none(v)
            for k, v in obj.items()
            if v is not None and prune_none(v) is not None
        }
    elif isinstance(obj, list):
        pruned = [prune_none(item) for item in obj]
        pruned = [item for item i…

15 0 Open

Dictionaries & sets easy

How to convert string values to int or float in Python dicts

Recursively convert string values in nested dicts and lists to ints or floats when possible, leaving other strings untouched.

dict type-conversion recursion

Python

def coerce_str_values(data):
    """Recursively convert string values that look like ints or floats."""
    if isinstance(data, dict):
        return {key: coerce_str_values(val) for key, val in data.items()}
    elif isinstance(data, list):
        return [coerce_str_values(item) for item in data]
    elif isinstance…

13 0 Open

Dictionaries & sets medium

Traverse Nested Dict Paths Depth-First in Python

Recursively walk a nested dictionary depth-first and yield each full path from root to leaf as lists.

recursion generators nested-dicts

Python

def depth_first_paths(node, path=None):
    if path is None:
        path = []
    
    if not isinstance(node, dict):
        yield path + [node]
        return
    
    for key, value in node.items():
        new_path = path + [key]
        if isinstance(value, dict):
            yield from depth_first_paths(value, …

13 0 Open

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