Add get_all_symbols function

[chrisjbremner]

I was looking for a way to retrieve all symbol information and came across #124, indicating this was not a feature. I searched the ADS repo for AdsReadSymbolInfo which #124 implies exists, but I could not find it.

The ability to read symbols was a feature I had used before in the counsyl-pyads package, so I decided to port over the logic. There's also logic in that package that allows you to read a symbol by name, but I decided against adding that for now unless there's a request to do so.

Here's a sample when tested with a PLC running TC3:

>>> symbols=plc.get_all_symbols()
>>> print('\n'.join("%s: %s" % item for item in vars(symbols[0]).items()))
index_group: 16448
index_offset: 384800
name: Constants.bFPUSupport
symtype: BOOL
comment: Does the target support multiple cores?

You may also notice that the import ordering was slightly modified to be in alphabetical order by isort. If this is not a desired change, I can revert it.

[coveralls]

Pull Request Test Coverage Report for Build 462

• 41 of 41 (100.0%) changed or added relevant lines in 4 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.3%) to 92.549%

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Totals
Change from base Build 449:	0.3%
Covered Lines:	795
Relevant Lines:	859

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💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 453

• 17 of 47 (36.17%) changed or added relevant lines in 4 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-3.1%) to 89.057%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pyads/utils.py	2	3	66.67%
pyads/structs.py	3	8	37.5%
pyads/ads.py	8	32	25.0%

Totals
Change from base Build 449:	-3.1%
Covered Lines:	765
Relevant Lines:	859

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💛 - Coveralls

[stlehmann]

Thanks for the PR. I find this to be a useful feature. So far it looks good for me. Please have a look at my review for minor change requests. Of course there also need to be some tests and documentation for the new feature. Would you like to take care of these, too?

[chrisjbremner]

I noticed that this was missing from the imports. Not strictly needed for this PR, so I can remove it from here if you'd prefer it in a separate PR.

[stlehmann]

Never mind. This is just a small import. No need to make a separate PR for it.

[chrisjbremner]

Thanks for taking a look, I've addressed your comments and added some tests and some documentation to the quickstart guide.

Regarding the import re-ordering, let me know if you'd prefer me to open a separate PR for reordering imports or if you'd like to leave it as is.

[stlehmann]

Looks great. Would you mind adding an entry to the Changelog. Then the PR is ready to merge.

[chrisjbremner]

Thanks for taking a look. I'm not able to merge, so feel free to do so yourself when you get a chance.

[stlehmann]

Thanks @chrisjbremner for the great work 👍

[chrisbeardy]

this is a great contribution!!!!

[chrisjbremner]

@stlehmann could I request a new release that incorporates this addition?

[stlehmann]

@chrisjbremner Yes, I think now is a good time for a new major release. I will get to it.

[stlehmann]

Release 3.3.0 is out.