如何为嵌套和fors的python代码编写jinja模板？

Question

I have written a python file to render a jinja template from the json data

import jinja2
from json import dumps

temploader = jinja2.FileSystemLoader(searchpath = '/')
tempenv = jinja2.Environment(loader=temploader,extensions=['jinja2.ext.loopcontrols'])
tempenv.filters['dumps'] = dumps

temp_file =  "/home/templates/myfile.tmpl"

temp = tempenv.get_template(temp_file)

ifconf = [
    {
    "Interface": "eth0", 
    "IP": "172.45.100.239", 
    "MAC": "48:4d:7e:55:4e:z8", 
    "Mask": "255.255.255.0", 
    "MTU": "1500"
   }, 
   {
    "Interface": "lo", 
    "IP": "127.0.0.1", 
    "MAC": "", 
    "Mask": "255.0.0.0", 
    "MTU": "65536"
   }, 
   {
    "Interface": "tun0", 
    "IP": "10.120.20.229", 
    "MAC": "00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00", 
    "Mask": "255.255.255.255", 
    "MTU": "1400"
   }, 
  {
    "Interface": "vboxnet0", 
    "IP": "192.168.43.1", 
    "MAC": "0a:00:27:00:00:00", 
    "Mask": "255.255.255.0", 
    "MTU": "1500"
  }
 ]


inp = {"data":ifconf}
out = temp.render(inp)
print out

Now, My desired output should be like this

{'Interface': ['eth0', 'lo', 'tun0', 'vboxnet0'], 'IP': ['172.23.106.239', '127.0.0.1', '10.120.233.229', '192.168.33.1'], 'MAC': ['48:4d:7e:9e:4e:b8', '', '00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00', '0a:00:27:00:00:00'], 'Mask': ['255.255.255.0', '255.0.0.0', '255.255.255.255', '255.255.255.0'], 'MTU': ['1500', '65536', '1400', '1500']}

The jinja template file : myfile.tmpl

{%- set di = dict.fromkeys(data[0],[]) -%}
{%- for i in data -%}
    {%- for k,v in di.items() -%}
        {%- for x,y in i.items() -%}
            {%- if x == k -%}
                 {%- set dummy = di[k].append(y)-%}
                 {%- break -%}
            {%- else -%}
                 {%- continue -%}
           {%- endif -%}          
       {%- endfor -%}
    {%- endfor -%}
{%- endfor -%}
{{di}}

I know break and continue doesn't work in jinja if I don't use loop control extensions. Even after using loop control extension I'm not getting the desired output.

Could you guys please help me:

1. To correct the jinja template using loop control extensions to get desired output

2. To get the desired output WITHOUT loop control extensions (since in my requirement is I should not be using loop control extensions.)

Answer 1

Firstly, there's no reason to do this in the template. Secondly, your logic could be simplified massively no matter where you do it:

keys = ifconf[0].keys()
data = {key: [val[key] for val in ifconf] for key in keys}

Answer 2

Try this :

dic = {}
for i in ifconf[0].keys():
    l = [j[i] for j in ifconf]
    dic[i] = l

print(dic)
{'IP': ['172.45.100.239', '127.0.0.1', '10.120.20.229', '192.168.43.1'],
 'Interface': ['eth0', 'lo', 'tun0', 'vboxnet0'],
 'MAC': ['48:4d:7e:55:4e:z8','','00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00',
  '0a:00:27:00:00:00'],
 'MTU': ['1500', '65536', '1400', '1500'],
 'Mask': ['255.255.255.0', '255.0.0.0', '255.255.255.255', '255.255.255.0']}

One liner:

>>> { i:[j[i] for j in ifconf] for i in ifconf[0].keys() }