-

cool-RR · cool-RR · commit a8c48d3fd13d · 2014-10-20T18:44:45.000+03:00
diff --git a/source_py2/python_toolbox/combi/misc.py b/source_py2/python_toolbox/combi/misc.py
@@ -0,0 +1,43 @@
+# Copyright 2009-2015 Ram Rachum.
+# This program is distributed under the MIT license.
+
+import math
+
+from python_toolbox import math_tools
+from python_toolbox import cute_iter_tools
+from python_toolbox import misc_tools
+
+infinity = float('inf')
+
+
+class MISSING_ELEMENT: 
+    '''A placeholder for a missing element used in internal calculations.'''
+        
+        
+@misc_tools.limit_positional_arguments(1)
+def get_short_factorial_string(number, minus_one=False):
+    '''
+    Get a short description of the factorial of `number`.
+    
+    If the number is long, just uses factorial notation. 
+    
+    Examples:
+    
+        >>> get_short_factorial_string(4)
+        '24'
+        >>> get_short_factorial_string(14)
+        '14!'
+    
+    '''
+    assert number >= 0 and \
+                    isinstance(number, math_tools.PossiblyInfiniteIntegral)
+    if number == infinity:
+        return "float('inf')"
+    elif number <= 10:
+        return str(math.factorial(number) - int(minus_one))
+    else:
+        assert number > 10
+        return '%s!%s' % (number, ' - 1' if minus_one else '')
+        
+
+    
diff --git a/source_py2/python_toolbox/combi/perming/comb_space.py b/source_py2/python_toolbox/combi/perming/comb_space.py
@@ -1,8 +1,11 @@
 # Copyright 2009-2015 Ram Rachum.
 # This program is distributed under the MIT license.
 
+from python_toolbox import misc_tools
+
 from .perm_space import PermSpace
 
+
 class CombSpace(PermSpace):
     '''
     A space of combinations.
@@ -29,7 +32,8 @@ class CombSpace(PermSpace):
     extra functionality. (See documentation of `Comb` and `Perm` for more
     info.)
     '''
-    def __init__(self, iterable_or_length, n_elements, *, slice_=None,
+    @misc_tools.limit_positional_arguments(3)
+    def __init__(self, iterable_or_length, n_elements, slice_=None,
                  perm_type=None, _domain_for_checking=None,
                  _degrees_for_checking=None):
         PermSpace.__init__(
diff --git a/source_py2/python_toolbox/combi/perming/perm.py b/source_py2/python_toolbox/combi/perming/perm.py
@@ -18,10 +18,11 @@
 infinity = float('inf')
 
 
-class _BasePermView(metaclass=abc.ABCMeta):
+class _BasePermView(object):
     '''
     Abstract base class for viewers on Perm.
     '''
+    __metaclass__ = abc.ABCMeta
     def __init__(self, perm):
         self.perm = perm
     __repr__ = lambda self: '<%s: %s>' % (type(self).__name__, self.perm)
@@ -69,8 +70,7 @@ def __call__(cls, item, perm_space=None):
         
 
 @functools.total_ordering
-class Perm(sequence_tools.CuteSequenceMixin, collections.Sequence,
-           metaclass=PermType):
+class Perm(sequence_tools.CuteSequenceMixin, collections.Sequence):
     '''
     A permutation of items from a `PermSpace`
     
@@ -87,6 +87,7 @@ class Perm(sequence_tools.CuteSequenceMixin, collections.Sequence,
         23
     
     '''
+    __metaclass__ = PermType
     
     @classmethod
     def coerce(cls, item, perm_space=None):
@@ -384,7 +385,8 @@ def n_cycles(self):
         return n_cycles
       
       
-    def get_neighbors(self, *, degrees=(1,), perm_space=None):
+    @misc_tools.limit_positional_arguments(1)
+    def get_neighbors(self, degrees=(1,), perm_space=None):
         '''
         Get the neighbor permutations of this permutation.
         
diff --git a/source_py2/python_toolbox/combi/perming/perm_space.py b/source_py2/python_toolbox/combi/perming/perm_space.py
@@ -16,6 +16,7 @@
 from python_toolbox import nifty_collections
 from python_toolbox import dict_tools
 from python_toolbox import misc_tools
+from python_toolbox.third_party import funcsigs
 
 from .. import misc
 from . import variations
@@ -54,7 +55,7 @@ def __call__(cls, *args, **kwargs):
                 _degrees_for_checking=arguments.get('degrees', None),
             )
         else:
-            return super().__call__(*args, **kwargs)
+            return super(PermSpaceType, cls).__call__(*args, **kwargs)
         
         
 class PermSpace(_VariationRemovingMixin, _VariationAddingMixin,
@@ -393,7 +394,7 @@ def __init__(self, iterable_or_length, n_elements=None, domain=None,
         if not self.is_typed:
             self.untyped = self
 
-    __init__.signature = inspect.signature(__init__)
+    __init__.signature = funcsigs.signature(__init__)
             
     @caching.CachedProperty
     def _unsliced_length(self):
