Pyvisa

-------------------

- deprecate methods that were mistakenly added to GPIB::INSTR resources PR 560
- fix the listing of available backends (Also not that we now return the backend
name as can be used to create a ResourceManger) PR 545
- allow a None value for the board value of a ResourceInfo PR 547
This allows for funky resource name such ASRL/dev/tty0::INSTR which are common
in pyvisa-py and avoid returning a completely generic resource in those cases.
- documentation improvements for pyvisa.resources.SerialInstrument PR 558

-------------------

- Fix reading binary values with an empty header PR 454
- Allow to use different headers in write_binary_values PR 454
- Remove `delay` kwarg from `read_ascii_values` which should never have been there PR 454
- Clarify the documentation about open_timeout PR 451

-----------------

- Change the returned data_length for IEEE block of undefined size to 0 PR 435
- Add chunk_size and data_length keyword argument to read/query_binary_values PR 435
- Make the ordering of the visa library deterministic PR 399
- Properly close pipes when looking for a shared library path on linux 380
- Fixing missing argument for USBInstrument.usb_control_out PR 353
- avoid attempting to close already closed resources in del PR 424
- add a list_opened_resources method to the ResourceManager PR 415
- use privately stored resource name in Resource class rather than relying on
VisaLibrary PR 415
- keep track of resources created by the ResourceManager to properly close them PR 357
- replace time.clock by time.perf_counter under Python 3 PR 441
- make the ordering of the visa library deterministic PR 399
- properly close pipes when looking for a shared library path on linux 380
- fixing missing argument for USBInstrument.usb_control_out PR 353
- usb_control_out -> control_out. warnings for deprecated usb_control_out PR 353
- Added new function log_to_stream() PR 363
- Made all enumerations of the `constants` module unique.
Fixed duplicate enums in StatusCode PR 371
- Use ni backend when specifying a file in open_visa_library PR 373
- Add flush() method to all resource classes that support viFlush()
(with the exception of VXIInstrument class) PR 390

------------------

- Add expect_termination argument to read_binary_values and
query_binary_values. This allows to retain the behavior of these methods from
pyvisa 1.8, where the length of the block of values that is being read did
not include the very final read termination. For instruments omitting the
termination character when transferring binary data, visa library raises a
timeout exception in case pyvisa 1.9.0 is used. Note that the behavior is not
reverted completely to its pyvisa 1.8 state because for other instruments
(for example, Keysight PNA on Ethernet) the termination character is indeed
added at the end of the message, and is not counted in the declared length in
the header. Prior to 1.9, if the last character of the binary block is also
the termination character, the actual termination could be missed, which
leads to hard to debug bugs hence the choice to preserve 1.9 behavior by
default. PR 349
- fix an encoding handling issue in setup.py PR 343
- if installed use pyvisa-py backend if a binary VISA implementation is not
installed. PR 341
- make custom exception hashable by removing __eq__. This should not impact
user code. PR 340
- fix an issue with the default value for GPIB secondary address in rname.py
PR 336
- ensure docstrings exist before manipulating them (attributes.py) PR 318
- documentation improvements PR 320 323

----------------

- Drop support for Python 2.6, 3.2 and 3.3 PR 300
- add the missing read_binary_values and read_ascii_values (PR 301)
- deprecate old methods in MessageBased (ask, read_values, query_values,
write_values, ask_delay) (PR 301)
- add support for hp headers in binary data (PR 301)
- fix encoding issue in write_ascii_values (PR 301)
- use import to load backend rather than pkgutil.iter_modules. This allows
PyVISA to support PyInstaller PR 307
- improvements to the visa shell: attributes type conversion (PR 299),
termchar command (PR 285), timeout command (PR 284),
support for non-default backend (PR 283), console script pyvisa-shell
(PR 286)
- improve speed for large data transfer by using bytearray instead of bytes
(PR 282)
- make Resource a context manager closing it. (PR 255)
- add 64 bits version of registry based functions (PR 278)
- make exceptions pickable (PR 249)
- add resource_name to the output of parse_resource_extended (PR 238)
- fix wait_on_event behavior in case of timeout (PR 234)
- allow selecting the backend using the PYVISA_LIBRARY env var (PR 195)