Create Pandas dataframe from JSON 基于嵌套列表构建

Question

I'd like to use the following nested list to:

• First: create a dictionary
• Second: from the dictionary, create a Pandas dataframe

structure=[['jumps', [['fox', [['The'], ['quick'], ['brown']]], ['over', [['dog', [['the'], ['lazy']]]]]]]]

This nested list comes from a parsed tree structure with dependencies:

          jumps              
       _____|________         
      |             over     
      |              |        
     fox            dog      
  ____|_____      ___|____    
The quick brown the      lazy

My idea was to transform this nested list in a JSON file, and after that create a Pandas dataframe looking like this one:

jumps fox
jumps over
fox The
fox quick
fox brown
over dog
dog the
dog lazy

So that this dataframe can be plotted with networkx .

I tried with json.dumps and dict without success so far.

Any insights are appreciated.

Answer 1

This is a tree-like structure, which makes me think that a recursive function should be used here. Here's how I would do that:

import pandas as pd

def recurse(l, parent=None):
    assert isinstance(l, list)
    for item in l:
        if isinstance(item, str):
            if parent is not None:
                yield (parent, item)
            parent = item
        elif isinstance(item, list):
            yield from recurse(item, parent)
        else:
            raise Exception(f"Unknown type {type(item)}")

structure=[['jumps', [['fox', [['The'], ['quick'], ['brown']]], ['over', [['dog', [['the'], ['lazy']]]]]]]]

df = pd.DataFrame(recurse(structure), columns=['from', 'to'])

How it works: it goes through each list, remembering what the last item it saw was. For each list it finds, it calls itself with that list. The output of this function is a generator which yields a tuple for each "edge" in your graph. This can be imported into a pandas dataframe.

Output:

    from     to
0  jumps    fox
1    fox    The
2    fox  quick
3    fox  brown
4  jumps   over
5   over    dog
6    dog    the
7    dog   lazy

Answer 2

I incorrectly read the question and assumed you wanted to plot the graph, instead of converting the nested list. @Nick's solution is the best way to go. Consider this answer only as additional information rather than a solution

Let's use graphviz and create our own DOT for the Digraph -

from graphviz import Source

l = [('jumps','fox'),
     ('jumps', 'over'),
     ('fox', 'The'),
     ('fox', 'quick'),
     ('fox', 'brown'),
     ('over', 'dog'),
     ('dog', 'the'),
     ('dog', 'lazy')]

dotgraph = 'digraph G {' + ' '.join([i+'->'+j for i,j in l]) + '}'
print(dotgraph)

s = Source(dotgraph, filename="test1.gv", format="png")
s.view()

digraph G {
    jumps->fox 
    jumps->over 
    fox->The 
    fox->quick 
    fox->brown 
    over->dog 
    dog->the 
    dog->lazy
}

You can play around with graphviz here on their visual editor. Also read the documentation for customization options on these graph elements and more complex graphs.