Add support for using ruamel.yaml instead of pyyaml where applicable.

Moved yaml import into compat.py to make the import happen once.
Added deprecation notice in README.md about pyyaml.

README.md

@@ -26,7 +26,23 @@ This readme contains a reduced version of the full documentation.
 Latest stable release from pypi
 
 ```
-$ pip install pykwalify
+pip install -e '.[ruamel]'
+```
+
+`PyYaml` deprecated and `ruamel.yaml` support.
+
+In release `1.6.0` `PyYaml` will be deprecated in favor of `ruamel.yaml`. `PyYaml` is still the default installed one but it will removed in release 1.7.0 and `ruamel.yaml` will be the new default one from that release and forward.
+
+You can install it for production use with
+
+```
+pip install 'pykwalify[ruamel]'
+```
+
+or for development use with
+
+```
+pip install -e '.[ruamel]'
 ```
 
 

docs/release-notes.rst

@@ -7,6 +7,12 @@ Next release (??? ?, 2016)
 - Convert all documentation to readthedocs
 - True/False is no longer considered valid integer
 - python3 'bytes' objects is now a valid strings and text type
+- The regular PyYaml support is now deprecated in favor of ruamel.yaml, see the following link for more details about
+  PyYaml being deprecated https://bitbucket.org/xi/pyyaml/issues/59/has-this-project-been-abandoned
+  PyYaml will still be possible to use in the next major release version (1.6.0) but removed in release (1.7.0) and forward.
+- ruamel.yaml is now possible to install with the following command for local development *pip install -e '.[ruamel]'*
+  and for production, use *pip install 'pykwalify[ruamel]'*
+- ruamel.yaml is now used before PyYaml if installed on your system
 
 
 1.5.1 (Mar 6, 2016)

docs/upgrade-instructions.rst

@@ -5,6 +5,13 @@ This document describes all major changes to the validation rules and the API th
 If new types were added, they will not be described here because it will not break existing schemas.
 
 
+1.5.x --> 1.6.0
+---------------
+
+ruamel.yaml is now possible to use as a drop-in replacement for PyYaml. Install it with *pip install 'pykwalify[ruamel]'* for production use and with *pip install -e '.[ruamel]'* for development use.
+
+PyYaml is now deprecated and will be removed in favor or ruamel.yaml in release 1.7.0.
+
 
 1.4.x --> 1.5.0
 ---------------

pykwalify/compat.py

@@ -2,6 +2,22 @@
 
 # python stdlib
 import sys
+import logging
+
+
+log = logging.getLogger(__name__)
+
+
+try:
+    from ruamel import yaml
+except ImportError:
+    try:
+        import yaml
+    except ImportError:
+        log.critical("Unable to import either ruamel.yaml or pyyaml")
+        sys.exit(1)
+
+log.debug("Using yaml library: {0}".format(yaml.__file__))
 
 
 if sys.version_info[0] < 3:

pykwalify/core.py

@@ -18,7 +18,7 @@
 from pykwalify.types import is_scalar, tt
 
 # 3rd party imports
-import yaml
+from pykwalify.compat import yaml
 from dateutil.parser import parse
 
 log = logging.getLogger(__name__)

setup.py

@@ -21,6 +21,9 @@
     license='MIT',
     packages=['pykwalify'],
     url='http://github.com/grokzen/pykwalify',
+    extras_require={
+        'ruamel': ["ruamel.yaml>=0.11.0,<0.12.0"],
+    },
     entry_points={
         'console_scripts': [
             'pykwalify = pykwalify.cli:cli_entrypoint',

tests/test_core.py

@@ -12,7 +12,7 @@
 
 # 3rd party imports
 import pytest
-import yaml
+from pykwalify.compat import yaml
 from testfixtures import compare
 
 

tests/test_unicode.py

@@ -12,7 +12,7 @@
 from pykwalify.errors import SchemaError
 
 # 3rd party imports
-import yaml
+from pykwalify.compat import yaml
 from testfixtures import compare