CODEWITHSUNDEEP
lualua-table
Maddy_15
Maddy_15

Reputation: 61

Converting Python function to Lua function

I am trying to convert existing python function into lua function. But my lua function is not producing same result as python function. Any help is appreciated.

Python function:

import json

test = '{"http://localhost:8080/":{"phone":{"-detail/phone detail.template.html":"5167n,a,7,2","s/motorola-xoom-with-wifi.json":"516a0,5,4,3"},"favicon.ico":"016ad,3,3,2","img/phones/motorola-xoom-with-wi-fi.":{"1.jpg":"*02s,2s,4v,h3|116da,o,l,6","2.jpg":"*02s,2s,4v,kp|116da,j,i,8","3.jpg":"*02s,2s,4v,ob|116da,o,m,8,7,,7,7,7","4.jpg":"*02s,2s,4v,rx|116da,o,m,9,8,,7,7,7","5.jpg":"*02s,2s,4v,vj|116da,p,m,a,8,,7,7,7"}}}'


def tri(param):
  t = {}
  for key in param:
    if key not in param:
        continue
    if isinstance(param[key], dict) and param[key] is not None:
        flat = tri(param[key])
        for x in flat:
            if x not in flat:
                continue
            t[key + x] = flat[x]
    else:
        t[key] = param[key]
return t


print(tri(json.loads(test)))

Lua code ( which is not producing same result as python function)

local json = require('cjson')

local test = '{"http://localhost:8080/":{"phone":{"-detail/phone-detail.template.html":"5167n,a,7,2","s/motorola-xoom-with-wi-fi.json":"516a0,5,4,3"},"favicon.ico":"016ad,3,3,2","img/phones/motorola-xoom-with-wi-fi.":{"1.jpg":"*02s,2s,4v,h3|116da,o,l,6","2.jpg":"*02s,2s,4v,kp|116da,j,i,8","3.jpg":"*02s,2s,4v,ob|116da,o,m,8,7,,7,7,7","4.jpg":"*02s,2s,4v,rx|116da,o,m,9,8,,7,7,7","5.jpg":"*02s,2s,4v,vj|116da,p,m,a,8,,7,7,7"}}}'

local function tri(param)
    t = {}
    for key in pairs(param) do
      if param[key] == nil then end
      if type(param[key]) == "table" then
        flat = tri(param[key])
        for k in pairs(flat) do
            t[key .. k] = flat[k]
        end
      else
        t[key] = param[key]
      end
  end
  return t
end


print(json.encode(tri(json.decode(test))))

Upvotes: 1

Views: 672

Answers (2)

Egor Skriptunoff
Egor Skriptunoff

Reputation: 23737

Your task could be done a bit easier using json.traverse() function from this Lua JSON module.
Traversing lets you perform arbitrary operations with JSON elements on-the-fly.

This code concatenates element's path (for every JSON element except JSON containers: arrays/objects) and uses it as a key for Lua table.

local json = require'json'

local t = {}

local function callback(path, json_type, value)
   if value ~= nil then  -- value == nil for containers (arrays/objects)
      t[table.concat(path)] = value
   end
end

local test = '{"http://localhost:8080/":{"phone":{"-detail/phone detail.template.html":"5167n,a,7,2","s/motorola-xoom-with-wifi.json":"516a0,5,4,3"},"favicon.ico":"016ad,3,3,2","img/phones/motorola-xoom-with-wi-fi.":{"1.jpg":"*02s,2s,4v,h3|116da,o,l,6","2.jpg":"*02s,2s,4v,kp|116da,j,i,8","3.jpg":"*02s,2s,4v,ob|116da,o,m,8,7,,7,7,7","4.jpg":"*02s,2s,4v,rx|116da,o,m,9,8,,7,7,7","5.jpg":"*02s,2s,4v,vj|116da,p,m,a,8,,7,7,7"}}}'

json.traverse(test, callback)

-- Now t == {
--    ["http://localhost:8080/favicon.ico"] = "016ad,3,3,2",
--    ["http://localhost:8080/img/phones/motorola-xoom-with-wi-fi.1.jpg"] = "*02s,2s,4v,h3|116da,o,l,6",
--    ["http://localhost:8080/img/phones/motorola-xoom-with-wi-fi.2.jpg"] = "*02s,2s,4v,kp|116da,j,i,8",
--    ["http://localhost:8080/img/phones/motorola-xoom-with-wi-fi.3.jpg"] = "*02s,2s,4v,ob|116da,o,m,8,7,,7,7,7",
--    ["http://localhost:8080/img/phones/motorola-xoom-with-wi-fi.4.jpg"] = "*02s,2s,4v,rx|116da,o,m,9,8,,7,7,7",
--    ["http://localhost:8080/img/phones/motorola-xoom-with-wi-fi.5.jpg"] = "*02s,2s,4v,vj|116da,p,m,a,8,,7,7,7",
--    ["http://localhost:8080/phone-detail/phone detail.template.html"] = "5167n,a,7,2",
--    ["http://localhost:8080/phones/motorola-xoom-with-wifi.json"] = "516a0,5,4,3"
-- }

Upvotes: 1

Piglet
Piglet

Reputation: 28950

local function tri(param)
    t = {}            -- every time we call tri t will be "reset" to an empty table
    for key in pairs(param) do
      if param[key] == nil then end
      if type(param[key]) == "table" then
        flat = tri(param[key])    -- here we call tri, but we still need t!
        for k in pairs(flat) do
            t[key .. k] = flat[k]
        end
      else
        t[key] = param[key]
      end
  end
  return t
end

Making at least t global should solve that problem. But there is also no reason for flat to be global so we make it local too.

local function tri(param)
    local t = {}
    for key in pairs(param) do
      if param[key] == nil then end
      if type(param[key]) == "table" then
        local flat = tri(param[key])
        for k in pairs(flat) do
            t[key .. k] = flat[k]
        end
      else
        t[key] = param[key]
      end
  end
  return t
end

Upvotes: 3

Related Questions