Fiona

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Bug fixes:

- The ensure_env_with_credentials decorator will no longer clobber credentials
of the outer environment. This fixes a bug reported to the Rasterio project
and which also existed in Fiona.
- An unused import of the packaging module and the dependency have been
removed (653).
- The Env class logged to the 'rasterio' hierarchy instead of 'fiona'. This
mistake has been corrected (646).
- The Mapping abstract base class is imported from collections.abc when
possible (647).

Refactoring:

- Standardization of the tests on pytest functions and fixtures continues and
is nearing completion (648, 649, 650, 651, 652).

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Deprecations:

- Collection slicing has been deprecated and will be prohibited in a future
version.

Bug fixes:

- Rasterio CRS objects passed to transform module methods will be converted
to dicts as needed (590).
- Implicitly convert curve geometries to their linear approximations rather
than failing (617).
- Migrated unittest test cases in test_collection.py and test_layer.py to the
use of the standard data_dir and path_coutwildrnp_shp fixtures (616).
- Root logger configuration has been removed from all test scripts (615).
- An AWS session is created for the CLI context Env only if explicitly
requested, matching the behavior of Rasterio's CLI (635).
- Dependency on attrs is made explicit.
- Other dependencies are pinned to known good versions in requirements files.
- Unused arguments have been removed from the Env constructor (637).

Refactoring:

- A with_context_env decorator has been added and used to set up the GDAL
environment for CLI commands. The command functions themselves are now
simplified.

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Deprecations:

- The ``fiona.drivers()`` context manager is officially deprecated. All
users should switch to ``fiona.Env()``, which registers format drivers and
manages GDAL configuration in a reversible manner.

Bug fixes:

- The Collection class now filters log messages about skipped fields to
a maximum of one warning message per field (627).
- The boto3 module is only imported when needed (507, 629).
- Compatibility with Click 7.0 is achieved (633).
- Use of %r instead of %s in a debug() call prevents UnicodeDecodeErrors
(620).

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New features:

- 64-bit integers are the now the default for int type fields (562, 564).
- 'http', 's3', 'zip+http', and 'zip+s3' URI schemes for datasets are now
supported (425, 426).
- We've added a ``MemoryFile`` class which supports formatted in-memory
feature collections (501).
- Added support for GDAL 2.x boolean field sub-type (531).
- A new ``fio rm`` command makes it possible to cleanly remove multi-file
datasets (538).
- The geometry type in a feature collection is more flexible. We can now
specify not only a single geometry type, but a sequence of permissible types,
or "Any" to permit any geometry type (539).
- Support for GDAL 2.2+ null fields has been added (554).
- The new ``gdal_open_vector()`` function of our internal API provides much
improved error handling (557).

Bug fixes:

- The bug involving OrderedDict import on Python 2.7 has been fixed (533).
- An ``AttributeError`` raised when the ``--bbox`` option of fio-cat is used
with more than one input file has been fixed (543, 544).
- Obsolete and derelict fiona.tool module has been removed.
- Revert the change in 0a2bc7c that discards Z in geometry types when a
collection's schema is reported (541).
- Require six version 1.7 or higher (550).
- A regression related to "zip+s3" URIs has been fixed.
- Debian's GDAL data locations are now searched by default (583).

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New features:

- Each call of ``writerecords()`` involves one or more transactions of up to
20,000 features each. This improves performance when writing GeoPackage files
as the previous transaction size was only 200 features (476, 491).

Packaging:

- Fiona's Cython source files have been refactored so that there are no longer
separate extension modules for GDAL 1.x and GDAL 2.x. Instead there is a base
extension module based on GDAL 2.x and shim modules for installations that
use GDAL 1.x.

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

- This post-release adds missing expat (and thereby GPX format) support to
the included GDAL library (still version 2.2.2).