py3: final fix for species

src/sage/combinat/species/series.py

@@ -14,7 +14,7 @@
 In particular, the relevant section for this file can be found at
 http://www.risc.uni-linz.ac.at/people/hemmecke/AldorCombinat/combinatse9.html.
 """
-#*****************************************************************************
+# ****************************************************************************
 #       Copyright (C) 2008 Mike Hansen <[email protected]>,
 #
 #  Distributed under the terms of the GNU General Public License (GPL)
@@ -26,8 +26,8 @@
 #
 #  The full text of the GPL is available at:
 #
-#                  http://www.gnu.org/licenses/
-#*****************************************************************************
+#                  https://www.gnu.org/licenses/
+# ****************************************************************************
 from __future__ import absolute_import
 
 from .stream import Stream, Stream_class
@@ -91,7 +91,7 @@ def __repr__(self):
             sage: LazyPowerSeriesRing(QQ)
             Lazy Power Series Ring over Rational Field
         """
-        return "Lazy Power Series Ring over %s"%self.base_ring()
+        return "Lazy Power Series Ring over %s" % self.base_ring()
 
     def __eq__(self, x):
         """
@@ -239,11 +239,11 @@ def __call__(self, x=None, order=unk):
             x = BR(x)
             return self.term(x, 0)
 
-        raise TypeError("do not know how to coerce %s into self"%x)
+        raise TypeError("do not know how to coerce %s into self" % x)
 
     def zero(self):
         """
-        Returns the zero power series.
+        Return the zero power series.
 
         EXAMPLES::
 
@@ -255,7 +255,7 @@ def zero(self):
 
     def identity_element(self):
         """
-        Returns the one power series.
+        Return the one power series.
 
         EXAMPLES::
 
@@ -303,13 +303,13 @@ def term(self, r, n):
             elif n == 1:
                 res._name = repr(r) + "*" + self._name
             else:
-                res._name = "%s*%s^%s"%(repr(r), self._name, n)
+                res._name = "%s*%s^%s" % (repr(r), self._name, n)
 
         return res
 
     def _new_initial(self, order, stream):
         """
-        Returns a new power series with specified order.
+        Return a new power series with specified order.
 
         INPUT:
 
@@ -596,7 +596,7 @@ def __repr__(self):
                 else:
                     l = baserepr + " + " + repr_lincomb([(x+"^"+str(i), self._stream[n-1]) for i in range(n, n+3)]) + " + ..."
             else:
-                l = baserepr + " + O(x^%s)"%n if n > 0 else "O(1)"
+                l = baserepr + " + O(x^%s)" % n if n > 0 else "O(1)"
         else:
             l = 'Uninitialized lazy power series'
         return l
@@ -739,7 +739,7 @@ def compute_coefficients(self, i):
 
     def coefficients(self, n):
         """
-        Returns the first n coefficients of self.
+        Return the first n coefficients of self.
 
         EXAMPLES::
 
@@ -752,7 +752,7 @@ def coefficients(self, n):
 
     def is_zero(self):
         """
-        Returns True if and only if self is zero.
+        Return True if and only if self is zero.
 
         EXAMPLES::
 
@@ -918,7 +918,7 @@ def define(self, x):
 
     def coefficient(self, n):
         """
-        Returns the coefficient of xn in self.
+        Return the coefficient of xn in self.
 
         EXAMPLES::
 
@@ -938,7 +938,7 @@ def coefficient(self, n):
 
     def get_aorder(self):
         """
-        Returns the approximate order of self.
+        Return the approximate order of self.
 
         EXAMPLES::
 
@@ -952,7 +952,7 @@ def get_aorder(self):
 
     def get_order(self):
         """
-        Returns the order of self.
+        Return the order of self.
 
         EXAMPLES::
 
@@ -966,7 +966,7 @@ def get_order(self):
 
     def get_stream(self):
         """
-        Returns self's underlying Stream object.
+        Return self's underlying Stream object.
 
         EXAMPLES::
 
@@ -1198,8 +1198,7 @@ def __pow__(self, n):
 
     def __call__(self, y):
         """
-        Returns the composition of this power series and the power series
-        y.
+        Return the composition of this power series and the power series y.
 
         EXAMPLES::
 
@@ -1267,7 +1266,7 @@ def _compose_gen(self, y, ao):
 
     def tail(self):
         """
-        Returns the power series whose coefficients obtained by subtracting
+        Return the power series whose coefficients obtained by subtracting
         the constant term from this series and then dividing by x.
 
         EXAMPLES::
@@ -1283,7 +1282,7 @@ def tail(self):
 
     def iterator(self, n=0, initial=None):
         """
-        Returns an iterator for the coefficients of self starting at n.
+        Return an iterator for the coefficients of self starting at n.
 
         EXAMPLES::
 
@@ -1308,7 +1307,7 @@ def iterator(self, n=0, initial=None):
 
     def _power_gen(self):
         """
-        Returns a generator for all the powers self^k starting with k = 1.
+        Return a generator for all the powers self^k starting with k = 1.
 
         EXAMPLES::
 
@@ -1388,8 +1387,7 @@ def derivative(self):
 
     def _diff_gen(self, ao):
         """
-        Returns an iterator for the coefficients of the derivative of
-        self.
+        Return an iterator for the coefficients of the derivative of self.
 
         EXAMPLES::
 
@@ -1601,7 +1599,7 @@ def exponential(self):
 
     def __getitem__(self, i):
         """
-        Returns the ith coefficient of self.
+        Return the ith coefficient of self.
 
         EXAMPLES::
 
@@ -1618,10 +1616,11 @@ def __getitem__(self, i):
     #########################
     def restricted(self, min=None, max=None):
         """
-        Returns the power series restricted to the coefficients starting at
-        min and going up to, but not including max. If min is not
-        specified, then it is assumed to be zero. If max is not specified,
-        then it is assumed to be infinity.
+        Return the power series restricted to the coefficients starting at
+        ``min`` and going up to, but not including ``max``.
+
+        If ``min`` is not specified, then it is assumed to be zero. If
+        ``max`` is not specified, then it is assumed to be infinity.
 
         EXAMPLES::
 
@@ -1637,10 +1636,13 @@ def restricted(self, min=None, max=None):
             [0, 0, 1, 1, 1, 1, 0, 0, 0, 0]
         """
         from six.moves import builtins
+
         if ((min is None and max is None) or
             (max is None and self.get_aorder() >= min)):
             return self
 
+        if min is None:
+            min = 0
         return self._new(partial(self._restricted_gen, min, max),
                          lambda ao: builtins.max(ao, min), self)