Replace cmp in acl_loader with operator.eq

[ZhaohuiS]

Signed-off-by: Zhaohui Sun zhaohuisun@microsoft.com

What I did

When run try to add a new rule for existing rule table with this command acl-loader update incremental, it will throw a traceback like this:

admin@vlab-03:~$ sudo acl-loader update incremental /home/admin/external_acl.json 
Traceback (most recent call last):
  File "/usr/local/bin/acl-loader", line 8, in <module>
    sys.exit(cli())
  File "/usr/local/lib/python3.9/dist-packages/click/core.py", line 764, in __call__
    return self.main(*args, **kwargs)
  File "/usr/local/lib/python3.9/dist-packages/click/core.py", line 717, in main
    rv = self.invoke(ctx)
  File "/usr/local/lib/python3.9/dist-packages/click/core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/local/lib/python3.9/dist-packages/click/core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/local/lib/python3.9/dist-packages/click/core.py", line 956, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/local/lib/python3.9/dist-packages/click/core.py", line 555, in invoke
    return callback(*args, **kwargs)
  File "/usr/local/lib/python3.9/dist-packages/click/decorators.py", line 17, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/usr/local/lib/python3.9/dist-packages/acl_loader/main.py", line 1066, in incremental
    acl_loader.incremental_update()
  File "/usr/local/lib/python3.9/dist-packages/acl_loader/main.py", line 761, in incremental_update
    if cmp(self.rules_info[key], self.rules_db_info[key]) != 0:
NameError: name 'cmp' is not defined

cmp is deprecated in python3.

How I did it

1. Use operator.eq instead.
   The return type of operator.eq is bool, it returns True if x is equal to y, False, otherwise.
   cmp syntax:
   cmp(a, b)
   Parameters:
   a and b are the two numbers in which the comparison is being done.
   Returns:
   -1 if a<b
   0 if a=b
   1 if a>b

2. Add unit test

How to verify it

Load acl json file with existing rule table in the config file with this command:
acl-loader update incremental**.json

Previous command output (if the output of a command-line utility has changed)

New command output (if the output of a command-line utility has changed)

[bingwang-ms]

Please update test case to cover the diff.

[qiluo-msft]

operator.eq will return a bool?

[ZhaohuiS]

@qiluo-msft Yes. The return type of this method is bool, it returns True if x is equal to y, False, otherwise.

[ZhaohuiS]

@qiluo-msft Thank you for your question, for python2, cmp returns 0 if x is equal to y, if not equal, the result is not 0, it should be -1 or 1. So, operator.eq's return result is opposite with cmp's results. I will update code to make the logic right and write unit test case as well.

Syntax:
cmp(a, b)
Parameters:
a and b are the two numbers in which the comparison is being done.
Returns:
-1 if a<b
0 if a=b
1 if a>b

[qiluo-msft]

I see your new iteration. To make it better, use if not eq().

[ZhaohuiS]

@qiluo-msft Ye, agree, I updated it.

[prsunny]

@ZhaohuiS , we need this for 202012 as well, correct? Can you please raise a separate PR?