json.dumps with indent prints different output

Question

This might be a silly question but I am quite new using json, and I do not fully understand this:

(Using this online compiler)

import json
print("Hello World")
print(json.dumps([1,2,3,{'4': 5, '6': 7}], separators=(',',':')))

As far as I've understood: json.dumps takes an object and produces a string

And the output seems right:

[1,2,3,{"6":7,"4":5}]

I searched for a way to make it more readable, and there is a parameter called indentthat does the job well. But I do not understand why the output is different.

print(json.dumps([1,2,3,{'4': 5, '6': 7}], indent=2, separators=(',',':')))

Output:

[                                                                                                                              
  1,                                                                                                                           
  2,                                                                                                                           
  3,                                                                                                                           
  {                                                                                                                            
    "6":7,                                                                                                                     
    "4":5                                                                                                                      
  }                                                                                                                            
] 

Shouldn't it be first "4":5, "6":7and not the other way around?

(Expected result?)

  [                                                                                                                              
      1,                                                                                                                           
      2,                                                                                                                           
      3,                                                                                                                           
      {                                                                                                                            
        "4":5,                                                                                                                     
        "6":7                                                                                                                      
      }                                                                                                                            
    ] 

Thanks in advance!