Drop 2.7 support

.appveyor.yml

@@ -14,10 +14,6 @@ environment:
   PYYAML_TEST_GROUP: all
 
 #  matrix:
-#    - PYTHON_VER: Python27
-#    - PYTHON_VER: Python27-x64
-#    - PYTHON_VER: Python35
-#    - PYTHON_VER: Python35-x64
 #    - PYTHON_VER: Python36
 #    - PYTHON_VER: Python36-x64
 #    - PYTHON_VER: Python37

.github/workflows/ci.yaml

@@ -118,7 +118,6 @@ jobs:
     strategy:
       matrix:
         cfg:
-        - { platform: manylinux1, arch: x86_64, python_tag: cp27-cp27mu }
         - { platform: manylinux1, arch: x86_64, python_tag: cp36-cp36m }
         - { platform: manylinux1, arch: x86_64, python_tag: cp37-cp37m }
         - { platform: manylinux1, arch: x86_64, python_tag: cp38-cp38 }
@@ -217,7 +216,6 @@ jobs:
         arch:
         - x86_64
         python_tag:
-        - cp27*
         - cp36*
         - cp37*
         - cp38*

.gitignore

@@ -2,7 +2,6 @@
 /dist/*
 /build/*
 /lib/PyYAML.egg-info/*
-/lib3/PyYAML.egg-info/*
 /wheelhouse/*
 /yaml/_yaml.c
 MANIFEST

MANIFEST.in

@@ -1,10 +1,7 @@
 include CHANGES README LICENSE Makefile pyproject.toml setup.py
 recursive-include lib/yaml *.py
 recursive-include lib/_yaml *.py
-recursive-include lib3/yaml *.py
-recursive-include lib3/_yaml *.py
 recursive-include examples *.py *.cfg *.yaml
 recursive-include tests/data *
 recursive-include tests/lib *.py
-recursive-include tests/lib3 *.py
 recursive-include yaml *

lib/yaml/__init__.py

@@ -1,21 +1,21 @@
 
-from error import *
+from .error import *
 
-from tokens import *
-from events import *
-from nodes import *
+from .tokens import *
+from .events import *
+from .nodes import *
 
-from loader import *
-from dumper import *
+from .loader import *
+from .dumper import *
 
 __version__ = '5.4.1'
-
 try:
-    from cyaml import *
+    from .cyaml import *
     __with_libyaml__ = True
 except ImportError:
     __with_libyaml__ = False
 
+import io
 
 #------------------------------------------------------------------------------
 # Warnings control
@@ -200,8 +200,7 @@ def emit(events, stream=None, Dumper=Dumper,
     """
     getvalue = None
     if stream is None:
-        from StringIO import StringIO
-        stream = StringIO()
+        stream = io.StringIO()
         getvalue = stream.getvalue
     dumper = Dumper(stream, canonical=canonical, indent=indent, width=width,
             allow_unicode=allow_unicode, line_break=line_break)
@@ -216,7 +215,7 @@ def emit(events, stream=None, Dumper=Dumper,
 def serialize_all(nodes, stream=None, Dumper=Dumper,
         canonical=None, indent=None, width=None,
         allow_unicode=None, line_break=None,
-        encoding='utf-8', explicit_start=None, explicit_end=None,
+        encoding=None, explicit_start=None, explicit_end=None,
         version=None, tags=None):
     """
     Serialize a sequence of representation trees into a YAML stream.
@@ -225,10 +224,9 @@ def serialize_all(nodes, stream=None, Dumper=Dumper,
     getvalue = None
     if stream is None:
         if encoding is None:
-            from StringIO import StringIO
+            stream = io.StringIO()
         else:
-            from cStringIO import StringIO
-        stream = StringIO()
+            stream = io.BytesIO()
         getvalue = stream.getvalue
     dumper = Dumper(stream, canonical=canonical, indent=indent, width=width,
             allow_unicode=allow_unicode, line_break=line_break,
@@ -255,7 +253,7 @@ def dump_all(documents, stream=None, Dumper=Dumper,
         default_style=None, default_flow_style=False,
         canonical=None, indent=None, width=None,
         allow_unicode=None, line_break=None,
-        encoding='utf-8', explicit_start=None, explicit_end=None,
+        encoding=None, explicit_start=None, explicit_end=None,
         version=None, tags=None, sort_keys=True):
     """
     Serialize a sequence of Python objects into a YAML stream.
@@ -264,10 +262,9 @@ def dump_all(documents, stream=None, Dumper=Dumper,
     getvalue = None
     if stream is None:
         if encoding is None:
-            from StringIO import StringIO
+            stream = io.StringIO()
         else:
-            from cStringIO import StringIO
-        stream = StringIO()
+            stream = io.BytesIO()
         getvalue = stream.getvalue
     dumper = Dumper(stream, default_style=default_style,
             default_flow_style=default_flow_style,
@@ -399,13 +396,12 @@ def __init__(cls, name, bases, kwds):
 
             cls.yaml_dumper.add_representer(cls, cls.to_yaml)
 
-class YAMLObject(object):
+class YAMLObject(metaclass=YAMLObjectMetaclass):
     """
     An object that can dump itself to a YAML stream
     and load itself from a YAML stream.
     """
 
-    __metaclass__ = YAMLObjectMetaclass
     __slots__ = ()  # no direct instantiation, so allow immutable subclasses
 
     yaml_loader = [Loader, FullLoader, UnsafeLoader]
@@ -414,18 +410,18 @@ class YAMLObject(object):
     yaml_tag = None
     yaml_flow_style = None
 
+    @classmethod
     def from_yaml(cls, loader, node):
         """
         Convert a representation node to a Python object.
         """
         return loader.construct_yaml_object(node, cls)
-    from_yaml = classmethod(from_yaml)
 
+    @classmethod
     def to_yaml(cls, dumper, data):
         """
         Convert a Python object to a representation node.
         """
         return dumper.represent_yaml_object(cls.yaml_tag, data, cls,
                 flow_style=cls.yaml_flow_style)
-    to_yaml = classmethod(to_yaml)
 

lib/yaml/composer.py

@@ -1,14 +1,14 @@
 
 __all__ = ['Composer', 'ComposerError']
 
-from error import MarkedYAMLError
-from events import *
-from nodes import *
+from .error import MarkedYAMLError
+from .events import *
+from .nodes import *
 
 class ComposerError(MarkedYAMLError):
     pass
 
-class Composer(object):
+class Composer:
 
     def __init__(self):
         self.anchors = {}
@@ -66,14 +66,14 @@ def compose_node(self, parent, index):
             anchor = event.anchor
             if anchor not in self.anchors:
                 raise ComposerError(None, None, "found undefined alias %r"
-                        % anchor.encode('utf-8'), event.start_mark)
+                        % anchor, event.start_mark)
             return self.anchors[anchor]
         event = self.peek_event()
         anchor = event.anchor
         if anchor is not None:
             if anchor in self.anchors:
                 raise ComposerError("found duplicate anchor %r; first occurrence"
-                        % anchor.encode('utf-8'), self.anchors[anchor].start_mark,
+                        % anchor, self.anchors[anchor].start_mark,
                         "second occurrence", event.start_mark)
         self.descend_resolver(parent, index)
         if self.check_event(ScalarEvent):
@@ -88,7 +88,7 @@ def compose_node(self, parent, index):
     def compose_scalar_node(self, anchor):
         event = self.get_event()
         tag = event.tag
-        if tag is None or tag == u'!':
+        if tag is None or tag == '!':
             tag = self.resolve(ScalarNode, event.value, event.implicit)
         node = ScalarNode(tag, event.value,
                 event.start_mark, event.end_mark, style=event.style)
@@ -99,7 +99,7 @@ def compose_scalar_node(self, anchor):
     def compose_sequence_node(self, anchor):
         start_event = self.get_event()
         tag = start_event.tag
-        if tag is None or tag == u'!':
+        if tag is None or tag == '!':
             tag = self.resolve(SequenceNode, None, start_event.implicit)
         node = SequenceNode(tag, [],
                 start_event.start_mark, None,
@@ -117,7 +117,7 @@ def compose_sequence_node(self, anchor):
     def compose_mapping_node(self, anchor):
         start_event = self.get_event()
         tag = start_event.tag
-        if tag is None or tag == u'!':
+        if tag is None or tag == '!':
             tag = self.resolve(MappingNode, None, start_event.implicit)
         node = MappingNode(tag, [],
                 start_event.start_mark, None,