JSON to Markdown table formatting

Question

I'm trying to build out a function to convert JSON data into a list to then be used as base for building out markdown tables.

I have a first prototype:

#!/usr/bin/env python3
import json

data = {
  "statistics": {
    "map": [
      {
        "map_name": "Location1",
        "nan": "loc1",
        "dont": "ignore this",
        "packets": "878607764338"
      },
      {
        "map_name": "Location2",
        "nan": "loc2",
        "dont": "ignore this",
        "packets": "67989088698"
      },
    ],
    "map-reset-time": "Thu Jan  6 05:59:47 2022\n"
  }
}
headers = ['Name', 'NaN', 'Packages']

def jsonToList(data):
    """adds the desired json fields"""
    # Wil be re-written to be more acceptant to different data fields. 
    json_obj = data

    ips = []
    for piece in json_obj['statistics']['map']:
        this_ip = [piece['map_name'], piece['nan'], piece['packets']]
        ips.append(this_ip)

    return ips 

def markdownTable(data, headers):
  # Find maximal length of all elements in list
    n = max(len(x) for l in data for x in l)
    # Print the rows
    headerLength = len(headers)
  
    # expected "|        Name|         NaN|    Packages|"
    for i in range(len(headers)):
      # Takes the max number of characters and subtracts the length of the header word
      hn = n - len(headers[i])
      # Prints | [space based on row above][header word]
      print("|" + " " * hn + f"{headers[i]}", end='')
      # If last run is meet add ending pipe
      if i == headerLength-1:
        print("|") # End pipe for headers

        # expected |--------|--------|--------|
        print("|", end='') # Start pipe for sep row
        for i in   range(len(headers)):
          print ("-" *n + "|", end='')

        # seams to be adding an extra line however if its not there,
        # Location1 
        print("\n", end='') 
        
    dataLength = len(data)
    for row in data:
      for x in row:
        hn = n - len(x)
        print(f"|" + " " * hn + x, end='')
      print("|")
 

if __name__ == "__main__":
    da = jsonToList(data)
    markdownTable(da, headers)

This code outputs as expected a table that can be used as markdown.

|        Name|         NaN|    Packages|
|------------|------------|------------|
|   Location1|        loc1|878607764338|
|   Location2|        loc2| 67989088698|

I was wondering if anyone have any good ideas regarding the placement of the words (centralized) currently I'm utilizing a n = max(len(x) for l in data for x in l) and then subtracts the length of the current string and ands it at the end of the output, this works well for left align but if would like to have them centered there's an issue.

Additionally general feedback on ways to optimize the code is much appreciated, if someone has build a similar function before this is my first attempt or ways to go directly from JSON.

Answer 1

If you are at a liberty to use pandas, this is quite straight forward. The markdown feature is readily available. See example below.

import pandas
df = pandas.DataFrame.from_dict(data['statistics']['map']).rename(columns={'map_name':'Name', 'nan':'NaN', 'packets':'Packages'})
df.drop(['dont'], axis=1, inplace=True)
print(df.to_markdown(index=False,tablefmt='fancy_grid'))

This will provide an output like:

╒═══════════╤═══════╤══════════════╕
│ Name      │ NaN   │     Packages │
╞═══════════╪═══════╪══════════════╡
│ Location1 │ loc1  │ 878607764338 │
├───────────┼───────┼──────────────┤
│ Location2 │ loc2  │  67989088698 │
╘═══════════╧═══════╧══════════════╛

You can use the tablefmt argument to apply different styles like psql, pipe etc.