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.

1 files changed, 1 insertions, 2 deletions

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,))