Remove (most of) the code intended for python 2

Framework/PythonInterface/mantid/api/_adsimports.py

@@ -85,7 +85,8 @@ def is_valid_identifier(name):
     """
     if _keyword.iskeyword(name):
         return False
-    # If the regex matches it is a valid identifier in Python 2.x
+    # If the regex matches it is a valid identifier
+    # Rules can be found here https://www.w3schools.com/python/gloss_python_variable_names.asp
     return IDENT_REGEX.match(name) is not None
 
 

Framework/PythonInterface/mantid/api/src/Exports/SpectrumInfoPythonIterator.cpp

@@ -7,9 +7,9 @@
 #include "MantidPythonInterface/api/SpectrumInfoPythonIterator.h"
 
 #include <boost/python/class.hpp>
-#include <boost/python/copy_const_reference.hpp>
 #include <boost/python/iterator.hpp>
 #include <boost/python/module.hpp>
+#include <boost/python/reference_existing_object.hpp>
 
 using Mantid::PythonInterface::SpectrumInfoPythonIterator;
 using namespace boost::python;
@@ -20,14 +20,5 @@ void export_SpectrumInfoPythonIterator() {
   // Export to Python
   class_<SpectrumInfoPythonIterator>("SpectrumInfoPythonIterator", no_init)
       .def("__iter__", objects::identity_function())
-      .def("__next__", &SpectrumInfoPythonIterator::next, return_value_policy<copy_const_reference>());
-  /*
-   Return value policy for next is to copy the const reference. Copy by value is
-   essential for python 2.0 compatibility because items (SpectrumInfoItem) will
-   outlive their iterators if declared as part of for loops. There is no good
-   way to deal with this other than to force a copy so that internals of the
-   item are not also corrupted. Future developers may wish to choose a separte
-   policy for python 3.0 where this is not a concern, and const ref returns
-   would be faster.
-  */
+      .def("__next__", &SpectrumInfoPythonIterator::next, return_value_policy<reference_existing_object>());
 }

Framework/PythonInterface/mantid/kernel/funcinspect.py

@@ -17,78 +17,14 @@
 import dis
 
 
-def replace_signature(func, signature):
-    """
-    Replace the signature of the given function object with that given by
-    varnames
-    :param func: Function whose signature is to be replaced
-    :param signature: A tuple of names of arguments and local variables in Python 2
-                      or a Signature object in Python 3
-    """
-    if hasattr(signature, "parameters"):
-        # A new Signature object
-        setattr(func, "__signature__", signature)
-    else:
-        # Drop this code when we dro Python 2 support
-        # Code object is different in Python 3
-        if hasattr(func, "func_code"):
-            # Version 2
-            code_attr = "func_code"
-            f = func.func_code
-            c = f.__new__(
-                f.__class__,
-                f.co_argcount,
-                f.co_nlocals,
-                f.co_stacksize,
-                f.co_flags,
-                f.co_code,
-                f.co_consts,
-                f.co_names,
-                signature,
-                f.co_filename,
-                f.co_name,
-                f.co_firstlineno,
-                f.co_lnotab,
-                f.co_freevars,
-            )
-        else:
-            code_attr = "__code__"
-            f = func.__code__
-            new_args = [
-                f.__class__,
-                f.co_argcount,
-                f.co_kwonlyargcount,
-                f.co_nlocals,
-                f.co_stacksize,
-                f.co_flags,
-                f.co_code,
-                f.co_consts,
-                f.co_names,
-                signature,
-                f.co_filename,
-                f.co_name,
-                f.co_firstlineno,
-                f.co_lnotab,
-                f.co_freevars,
-            ]
-            # Python 3.8 supports positional-only arguments and has an extra
-            # keyword in the constructor
-            if hasattr(f, "co_posonlyargcount"):
-                new_args.insert(2, f.co_posonlyargcount)
-            c = f.__new__(*new_args)
-        # endif
-        setattr(func, code_attr, c)
-
-
 def customise_func(func, name, signature, docstring):
     """
     Takes the definition of the algorithm function and replaces
     the attributes of the instance to make it look like a handwritten
     function definition
     :param func: A function object holding the definition
     :param name: The name of the algorithm
-    :param signature: A new signature for the function. Expecting a 2-tuple
-                      of arguments and local variables. See _replace_signature
+    :param signature: A new signature for the function
     :param docstring: A string containing the function documentation
     """
     func.__name__ = str(name)
@@ -106,7 +42,7 @@ class LazyFunctionSignature(inspect.Signature):
     to reduce the time spent initialising algorithms.
     """
 
-    __slots__ = ("_alg_name", "__sig")
+    __slots__ = ("_alg_name", "__sig", "_include_self")
 
     def __init__(self, *args, **kwargs):
         if "alg_name" not in kwargs:
@@ -116,6 +52,11 @@ def __init__(self, *args, **kwargs):
             self._alg_name = kwargs.pop("alg_name")
             self.__sig = None
 
+        if "include_self" in kwargs:
+            self._include_self = kwargs.pop("include_self")
+        else:
+            self._include_self = True
+
     @property
     def _signature(self):
         if self.__sig is None:
@@ -157,8 +98,9 @@ def _create_parameters(self, alg_name):
                 # None is not quite accurate here, but we are reproducing the
                 # behavior found in the C++ code for SimpleAPI.
                 parameters.append(Parameter(name, pos_or_keyword, default=None))
-        # Add a self parameter since these are called from a class.
-        parameters.insert(0, Parameter("self", Parameter.POSITIONAL_ONLY))
+        if self._include_self:
+            # Add a self parameter since these are called from a class.
+            parameters.insert(0, Parameter("self", Parameter.POSITIONAL_ONLY))
         return parameters
 
 

Framework/PythonInterface/mantid/simpleapi.py

@@ -41,11 +41,9 @@
 from mantid import api as _api, kernel as _kernel
 from mantid import apiVersion  # noqa: F401
 from mantid.kernel import plugins as _plugin_helper
-from mantid.kernel import ConfigService, logger
 from mantid.kernel.funcinspect import (
     customise_func as _customise_func,
     lhs_info as _lhs_info,
-    replace_signature as _replace_signature,
     LazyFunctionSignature,
 )
 
@@ -321,7 +319,7 @@ def wrapper(*args, **kwargs):
 
         # end
         function_name = f.__name__
-        signature = ("\bFunction, InputWorkspace", "**kwargs")
+        signature = LazyFunctionSignature(alg_name=function_name, include_self=False)
         fwrapper = _customise_func(wrapper, function_name, signature, f.__doc__)
         if function_name not in __SPECIALIZED_FUNCTIONS__:
             __SPECIALIZED_FUNCTIONS__.append(function_name)
@@ -527,7 +525,7 @@ def CutMD(*args, **kwargs):  # noqa: C901
         return out_names[0]
 
 
-_replace_signature(CutMD, ("\bInputWorkspace", "**kwargs"))
+CutMD.__signature__ = LazyFunctionSignature(alg_name="CutMD", include_self=False)
 
 
 def RenameWorkspace(*args, **kwargs):
@@ -572,7 +570,7 @@ def RenameWorkspace(*args, **kwargs):
     return _gather_returns("RenameWorkspace", lhs, algm)
 
 
-_replace_signature(RenameWorkspace, ("\bInputWorkspace,[OutputWorkspace],[True||False]", "**kwargs"))
+RenameWorkspace.__signature__ = LazyFunctionSignature(alg_name="RenameWorkspace", include_self=False)
 
 
 def _get_function_spec(func):
@@ -1179,23 +1177,6 @@ def get_self(frame_arg):
 # ----------------------------------------------------------------------------------------------------------------------
 
 
-def _create_fake_function(name):
-    """Create fake functions for the given name"""
-
-    # ------------------------------------------------------------------------------------------------
-    def fake_function(*args, **kwargs):
-        raise RuntimeError(
-            "Mantid import error. The mock simple API functions have not been replaced!"
-            " This is an error in the core setup logic of the mantid module, "
-            "please contact the development team."
-        )
-
-    # ------------------------------------------------------------------------------------------------
-    fake_function.__name__ = name
-    _replace_signature(fake_function, ("", ""))
-    globals()[name] = fake_function
-
-
 def _mockup(plugins):
     """
     Creates fake, error-raising functions for any plugins given.

Framework/PythonInterface/plugins/algorithms/BASISCrystalDiffraction.py

@@ -274,7 +274,6 @@ def PyExec(self):
         # Facility and database configuration
         config_new_options = {"default.facility": "SNS", "default.instrument": "BASIS", "datasearch.searcharchive": "On"}
 
-        # implement with ContextDecorator after python2 is deprecated)
         with pyexec_setup(config_new_options) as self._temps:
             # Load the mask to a temporary workspace
             self._t_mask = LoadMask(Instrument="BASIS", InputFile=self.getProperty("MaskFile").value, OutputWorkspace="_t_mask")

Framework/PythonInterface/plugins/algorithms/BASISDiffraction.py

@@ -237,7 +237,6 @@ def PyExec(self):
         self._lambda_range = np.array(self.getProperty("LambdaRange").value)
         self._momentum_range = np.sort(2 * np.pi / self._lambda_range)
 
-        # implement with ContextDecorator after python2 is deprecated)
         with pyexec_setup(config_new_options) as self._temps:
             # Load the mask to a workspace
             self._t_mask = LoadMask(Instrument="BASIS", InputFile=self.getProperty("MaskFile").value, OutputWorkspace="_t_mask")

Framework/PythonInterface/plugins/algorithms/BASISPowderDiffraction.py

@@ -314,9 +314,6 @@ def PyExec(self):
         # Find desired Q-binning
         #
         self._qbins = np.array(self.getProperty("MomentumTransferBins").value)
-        #
-        # implement with ContextDecorator after python2 is deprecated)
-        #
         remove_temp = self.getProperty("RemoveTemporaryWorkspaces").value
         with pyexec_setup(remove_temp, config_new_options) as self._temps:
             #

Framework/PythonInterface/plugins/algorithms/BASISReduction.py

@@ -354,9 +354,6 @@ def PyInit(self):
     def PyExec(self):
         # Facility and database configuration
         config_new_options = {"default.facility": "SNS", "default.instrument": "BASIS", "datasearch.searcharchive": "On"}
-        #
-        # implement with ContextDecorator after python2 is deprecated)
-        #
         remove_temp = self.getProperty("RemoveTemporaryWorkspaces").value
         with pyexec_setup(remove_temp, config_new_options) as self._temps:
             self._PyExec()

Framework/PythonInterface/plugins/algorithms/LoadEXED.py

@@ -22,13 +22,6 @@
 import struct
 import numpy as np
 import copy
-import types
-
-# Unicode type for both python2 and 3
-try:
-    UnicodeType = types.UnicodeType
-except AttributeError:
-    UnicodeType = str
 
 
 class LoadEXED(PythonAlgorithm):
@@ -121,7 +114,7 @@ def PyExec(self):
             ws.getSpectrum(i).setDetectorID(det_udet[i])
         # Sample_logs the header values are written into the sample logs
         log_names = [str(sl.encode("ascii", "ignore").decode()) for sl in parms_dict.keys()]
-        log_values = [str(sl.encode("ascii", "ignore").decode()) if isinstance(sl, UnicodeType) else str(sl) for sl in parms_dict.values()]
+        log_values = [str(sl.encode("ascii", "ignore").decode()) if isinstance(sl, str) else str(sl) for sl in parms_dict.values()]
         for i in range(len(log_values)):
             if ("nan" in log_values[i]) or ("NaN" in log_values[i]):
                 log_values[i] = "-1.0"

Framework/PythonInterface/plugins/algorithms/SaveGEMMAUDParamFile.py

@@ -8,7 +8,6 @@
 import os
 import re
 from collections import defaultdict
-from string import Formatter
 
 from mantid.api import *
 from mantid.kernel import *
@@ -115,9 +114,7 @@ def create_empty_param_list(default_value="0"):
         output_params["bank_ids"] = "\n".join("Bank{}".format(i + 1) for i in range(num_banks))
 
         with open(self.getProperty(self.PROP_OUTPUT_FILE).value, "w") as output_file:
-            # Note, once we've got rid of Python 2 support this can be simplified to
-            # template.format_map(**defaultdict(create_empty_param_list, output_params))
-            output_file.write(Formatter().vformat(template, (), defaultdict(create_empty_param_list, output_params)))
+            output_file.write(template.format_map(defaultdict(create_empty_param_list, output_params)))
 
     def validateInputs(self):
         issues = {}

Framework/PythonInterface/test/python/mantid/api/MDHistoWorkspaceTest.py

@@ -10,13 +10,6 @@
 
 import numpy
 
-try:
-    long
-except NameError:
-    # Defined for backwards compatability with Python 2
-    def long(x):
-        return x
-
 
 class MDHistoWorkspaceTest(unittest.TestCase):
     """
@@ -321,7 +314,7 @@ def test_integrated_bin(self):
         )
         BH = mtd["BH"]
         signal = BH.getSignalArray()
-        expected = (long(20), long(1), long(30))
+        expected = (20, 1, 30)
         shape = signal.shape
         self.assertEqual(shape, expected)
         mtd.remove("BH")
@@ -339,7 +332,7 @@ def test_composed_bin(self):
         )
         BH = mtd["BH"]
         signal = BH.getSignalArray()
-        expected = (long(20), long(1))
+        expected = (20, 1)
         shape = signal.shape
         self.assertEqual(shape, expected)
         mtd.remove("BH")
@@ -375,7 +368,7 @@ def test_heterogeneous_bin(self):
         nEvents = BH.getNEvents()
         self.assertEqual(nEvents, 1000)
         signal = BH.getSignalArray()
-        expected = (long(20), long(5), long(40))
+        expected = (20, 5, 40)
         shape = signal.shape
         self.assertEqual(shape, expected)