MAINT: Apply 2to3 idioms fixer.

The idioms fixer makes the following replacements.

1) int <- bool
2) comparison or identity of types <- isinstance
3) a.sort() <- sorted(a)

There were two problems that needed to be dealt with after the
application of the fixer. First, the replacement of comparison or
identity of types by isinstance was not always correct.  The isinstance
function returns true for subtypes whereas many of the places where the
fixer made a substitution needed to check for exact type equality.
Second, the sorted function was applied to arrays, but because it treats
them as iterators and constructs a sorted list from the result, that is
the wrong thing to do.

Closes #3062.

9 files changed, 15 insertions, 19 deletions

diff --git a/numpy/lib/arrayterator.py b/numpy/lib/arrayterator.py
index 094d41c11..c2cde574e 100644
--- a/numpy/lib/arrayterator.py
+++ b/numpy/lib/arrayterator.py
@@ -188,7 +188,7 @@ class Arrayterator(object):
         step = self.step[:]
         ndims = len(self.var.shape)
 
-        while 1:
+        while True:
             count = self.buf_size or reduce(mul, self.shape)
 
             # iterate over each dimension, looking for the
diff --git a/numpy/lib/format.py b/numpy/lib/format.py
index 40788e148..81e8cd010 100644
--- a/numpy/lib/format.py
+++ b/numpy/lib/format.py
@@ -344,8 +344,7 @@ def read_array_header_1_0(fp):
     if not isinstance(d, dict):
         msg = "Header is not a dictionary: %r"
         raise ValueError(msg % d)
-    keys = list(d.keys())
-    keys.sort()
+    keys = sorted(d.keys())
     if keys != ['descr', 'fortran_order', 'shape']:
         msg = "Header does not contain the correct keys: %r"
         raise ValueError(msg % (keys,))
diff --git a/numpy/lib/function_base.py b/numpy/lib/function_base.py
index 1ead53c87..a7163a7ca 100644
--- a/numpy/lib/function_base.py
+++ b/numpy/lib/function_base.py
@@ -1273,8 +1273,7 @@ def unique(x):
         idx = concatenate(([True],tmp[1:]!=tmp[:-1]))
         return tmp[idx]
     except AttributeError:
-        items = list(set(x))
-        items.sort()
+        items = sorted(set(x))
         return asarray(items)
 
 def extract(condition, arr):
diff --git a/numpy/lib/index_tricks.py b/numpy/lib/index_tricks.py
index 314cba120..b3c9b72bc 100644
--- a/numpy/lib/index_tricks.py
+++ b/numpy/lib/index_tricks.py
@@ -244,7 +244,7 @@ class AxisConcatenator(object):
             frame = sys._getframe().f_back
             mymat = matrix.bmat(key,frame.f_globals,frame.f_locals)
             return mymat
-        if type(key) is not tuple:
+        if not isinstance(key, tuple):
             key = (key,)
         objs = []
         scalars = []
@@ -252,7 +252,7 @@ class AxisConcatenator(object):
         scalartypes = []
         for k in range(len(key)):
             scalar = False
-            if type(key[k]) is slice:
+            if isinstance(key[k], slice):
                 step = key[k].step
                 start = key[k].start
                 stop = key[k].stop
@@ -627,7 +627,7 @@ class IndexExpression(object):
         self.maketuple = maketuple
 
     def __getitem__(self, item):
-        if self.maketuple and type(item) != tuple:
+        if self.maketuple and not isinstance(item, tuple):
             return (item,)
         else:
             return item
diff --git a/numpy/lib/npyio.py b/numpy/lib/npyio.py
index c13c7e94a..fbcb5a46e 100644
--- a/numpy/lib/npyio.py
+++ b/numpy/lib/npyio.py
@@ -1025,7 +1025,7 @@ def savetxt(fname, X, fmt='%.18e', delimiter=' ', newline='\n', header='',
             if len(fmt) != ncol:
                 raise AttributeError('fmt has wrong shape.  %s' % str(fmt))
             format = asstr(delimiter).join(map(asstr, fmt))
-        elif type(fmt) is str:
+        elif isinstance(fmt, str):
             n_fmt_chars = fmt.count('%')
             error = ValueError('fmt has wrong number of %% formats:  %s' % fmt)
             if n_fmt_chars == 1:
diff --git a/numpy/lib/polynomial.py b/numpy/lib/polynomial.py
index e61a89b87..5402adc6d 100644
--- a/numpy/lib/polynomial.py
+++ b/numpy/lib/polynomial.py
@@ -905,7 +905,7 @@ def _raise_power(astr, wrap=70):
     line1 = ''
     line2 = ''
     output = ' '
-    while 1:
+    while True:
         mat = _poly_mat.search(astr, n)
         if mat is None:
             break
diff --git a/numpy/lib/shape_base.py b/numpy/lib/shape_base.py
index de8606167..5357c62df 100644
--- a/numpy/lib/shape_base.py
+++ b/numpy/lib/shape_base.py
@@ -643,10 +643,9 @@ def get_array_prepare(*args):
 
     In case of ties, leftmost wins. If no wrapper is found, return None
     """
-    wrappers = [(getattr(x, '__array_priority__', 0), -i,
+    wrappers = sorted((getattr(x, '__array_priority__', 0), -i,
                  x.__array_prepare__) for i, x in enumerate(args)
-                                   if hasattr(x, '__array_prepare__')]
-    wrappers.sort()
+                                   if hasattr(x, '__array_prepare__'))
     if wrappers:
         return wrappers[-1][-1]
     return None
@@ -656,10 +655,9 @@ def get_array_wrap(*args):
 
     In case of ties, leftmost wins. If no wrapper is found, return None
     """
-    wrappers = [(getattr(x, '__array_priority__', 0), -i,
+    wrappers = sorted((getattr(x, '__array_priority__', 0), -i,
                  x.__array_wrap__) for i, x in enumerate(args)
-                                   if hasattr(x, '__array_wrap__')]
-    wrappers.sort()
+                                   if hasattr(x, '__array_wrap__'))
     if wrappers:
         return wrappers[-1][-1]
     return None
diff --git a/numpy/lib/type_check.py b/numpy/lib/type_check.py
index 6e0cfcddb..cb9b6ee49 100644
--- a/numpy/lib/type_check.py
+++ b/numpy/lib/type_check.py
@@ -58,7 +58,7 @@ def mintypecode(typechars,typeset='GDFgdf',default='d'):
     'G'
 
     """
-    typecodes = [(type(t) is type('') and t) or asarray(t).dtype.char\
+    typecodes = [(isinstance(t, str) and t) or asarray(t).dtype.char\
                  for t in typechars]
     intersection = [t for t in typecodes if t in typeset]
     if not intersection:
diff --git a/numpy/lib/utils.py b/numpy/lib/utils.py
index 2519cd4d4..f94abeeab 100644
--- a/numpy/lib/utils.py
+++ b/numpy/lib/utils.py
@@ -435,7 +435,7 @@ def _makenamedict(module='numpy'):
     thedict = {module.__name__:module.__dict__}
     dictlist = [module.__name__]
     totraverse = [module.__dict__]
-    while 1:
+    while True:
         if len(totraverse) == 0:
             break
         thisdict = totraverse.pop(0)
@@ -584,7 +584,7 @@ def info(object=None,maxwidth=76,output=sys.stdout,toplevel='numpy'):
                     methstr, other = pydoc.splitdoc(inspect.getdoc(thisobj) or "None")
                 print("  %s  --  %s" % (meth, methstr), file=output)
 
-    elif type(object) is types.InstanceType: ## check for __call__ method
+    elif isinstance(object, types.InstanceType): ## check for __call__ method
         print("Instance of class: ", object.__class__.__name__, file=output)
         print(file=output)
         if hasattr(object, '__call__'):