Remove workarounds and backports for Python 2 support

In particular:
- In common/, remove the backport of weakref.WeakMethod
- In docs/ and ui/, use the standard FileNotFoundError class
- Use built-in open() instead of io.open(), and stop importing io
- In core/stats.py, use the standard implementation of xml.etree instead
of the C one

bin/meshroom_batch

@@ -144,9 +144,8 @@ with multiview.GraphModification(graph):
         publish.output.value = args.output
 
     if args.overrides:
-        import io
         import json
-        with io.open(args.overrides, 'r', encoding='utf-8', errors='ignore') as f:
+        with open(args.overrides, 'r', encoding='utf-8', errors='ignore') as f:
             data = json.load(f)
             for nodeName, overrides in data.items():
                 for attrName, value in overrides.items():

docs/source/_ext/fetch_md.py

@@ -17,12 +17,6 @@ from docutils.nodes import SparseNodeVisitor
 from docutils.parsers.rst import Directive
 from utils import md_to_docutils, get_link_key
 
-# Python2 compatibility
-try:
-    FileNotFoundError
-except NameError:
-    FileNotFoundError = IOError
-
 
 class Relinker(SparseNodeVisitor):
 

meshroom/common/PySignal.py

@@ -13,59 +13,7 @@ import inspect
 import sys
 import weakref
 from functools import partial
-
-
-# weakref.WeakMethod backport
-try:
-    from weakref import WeakMethod
-
-except ImportError:
-    import types
-
-    class WeakMethod(object):
-        """Light WeakMethod backport compiled from various sources. Tested in 2.7"""
-
-        def __init__(self, func):
-            if inspect.ismethod(func):
-                self._obj = weakref.ref(func.__self__)
-                self._func = weakref.ref(func.__func__)
-
-            else:
-                self._obj = None
-
-                try:
-                    self._func = weakref.ref(func.__func__)
-
-                # Rather than attempting to handle this, raise the same exception
-                # you get from WeakMethod.
-                except AttributeError:
-                    raise TypeError("argument should be a bound method, not %s" % type(func))
-
-        def __call__(self):
-            if self._obj is not None:
-                obj = self._obj()
-                func = self._func()
-                if func is None or obj is None:
-                    return None
-
-                else:
-                    return types.MethodType(func, obj, obj.__class__)
-
-            elif self._func is not None:
-                return self._func()
-
-            else:
-                return None
-
-        def __eq__(self, other):
-            try:
-                return type(self) is type(other) and self() == other()
-
-            except Exception:
-                return False
-
-        def __ne__(self, other):
-            return not self.__eq__(other)
+from weakref import WeakMethod
 
 
 class Signal(object):

meshroom/core/desc.py

@@ -1,7 +1,7 @@
 from meshroom.common import BaseObject, Property, Variant, VariantList, JSValue
 
 from collections.abc import Iterable
-from enum import Enum  # available by default in python3. For python2: "pip install enum34"
+from enum import Enum
 import math
 import os
 import psutil
@@ -254,9 +254,7 @@ class IntParam(Param):
     def validateValue(self, value):
         # handle unsigned int values that are translated to int by shiboken and may overflow
         try:
-            return long(value)  # Python 2
-        except NameError:
-            return int(value)   # Python 3
+            return int(value)
         except:
             raise ValueError('IntParam only supports int value (param:{}, value:{}, type:{})'.format(self.name, value, type(value)))
 

meshroom/core/node.py

@@ -510,8 +510,7 @@ class BaseNode(BaseObject):
     def __getattr__(self, k):
         try:
             # Throws exception if not in prototype chain
-            # return object.__getattribute__(self, k) # doesn't work in python2
-            return object.__getattr__(self, k)
+            return object.__getattribute__(self, k)
         except AttributeError as e:
             try:
                 return self.attribute(k)

meshroom/core/stats.py

@@ -8,11 +8,7 @@ import platform
 import os
 import sys
 
-if sys.version_info[0] == 2:
-    # On Python 2 use C implementation for performance and to avoid lots of warnings
-    from xml.etree import cElementTree as ET
-else:
-    import xml.etree.ElementTree as ET
+import xml.etree.ElementTree as ET
 
 
 def bytes2human(n):
@@ -95,11 +91,7 @@ class ComputerStatistics:
             return
         try:
             p = subprocess.Popen([self.nvidia_smi, "-q", "-x"], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-            if sys.version_info[0] == 2:
-                # no timeout in python-2
-                xmlGpu, stdError = p.communicate()
-            else:
-                xmlGpu, stdError = p.communicate(timeout=10) # 10 seconds
+            xmlGpu, stdError = p.communicate(timeout=10) # 10 seconds
 
             smiTree = ET.fromstring(xmlGpu)
             gpuTree = smiTree.find('gpu')

meshroom/core/taskManager.py

@@ -348,7 +348,7 @@ class TaskManager(BaseObject):
                 raise ValueError("Argument 'context' must be: 'COMPUTATION' or 'SUBMITTING'")
 
         if len(ready) + len(computed) != len(toNodes):
-            del toNodes[:]  # for python 2 compatibility, else use: toNodes.clear()
+            toNodes.clear()
             toNodes.extend(ready)
             return False
 

meshroom/nodes/aliceVision/CameraInit.py

@@ -94,9 +94,8 @@ def readSfMData(sfmFile):
     Returns:
         The views and intrinsics of the .sfm as two separate lists
     """
-    import io  # use io.open for Python2/3 compatibility (allow to specify encoding + errors handling)
     # skip decoding errors to avoid potential exceptions due to non utf-8 characters in images metadata
-    with io.open(sfmFile, 'r', encoding='utf-8', errors='ignore') as f:
+    with open(sfmFile, 'r', encoding='utf-8', errors='ignore') as f:
         data = json.load(f)
 
     intrinsicsKeys = [i.name for i in Intrinsic]

meshroom/ui/reconstruction.py

@@ -17,12 +17,6 @@ from meshroom.core.node import Node, CompatibilityNode, Status, Position
 from meshroom.ui.graph import UIGraph
 from meshroom.ui.utils import makeProperty
 
-# Python2 compatibility
-try:
-    FileNotFoundError
-except NameError:
-    FileNotFoundError = IOError
-
 
 class Message(QObject):
     """ Simple structure wrapping a high-level message. """
@@ -623,9 +617,8 @@ class Reconstruction(UIGraph):
         sfmFile = panoramaInit.attribute('outSfMData').value
         if not os.path.exists(sfmFile):
             return QVector3D(0.0, 0.0, 0.0)
-        import io  # use io.open for Python2/3 compatibility (allow to specify encoding + errors handling)
         # skip decoding errors to avoid potential exceptions due to non utf-8 characters in images metadata
-        with io.open(sfmFile, 'r', encoding='utf-8', errors='ignore') as f:
+        with open(sfmFile, 'r', encoding='utf-8', errors='ignore') as f:
             data = json.load(f)
 
         intrinsics = data.get('intrinsics', [])