ENH: drop use of Counter in favor of MB's shared snippet using recipe from scipy

+ adjusted the test which for some reason has failed on me although I don't think I have done
any related changes here

Author: yarikoptic

bin/nib-ls

@@ -22,7 +22,6 @@ import sys
 from math import ceil
 from optparse import OptionParser, Option
 from io import StringIO
-from collections import Counter
 
 import numpy as np
 
@@ -231,10 +230,9 @@ def proc_file(f, opts):
                 # stats
                 row += [len(d) and '@l[%.2g, %.2g]' % (np.min(d), np.max(d)) or '-']
             if opts.counts:
-                counter = Counter()
-                counter.update(d.flatten())
-                # go through each entry and report only non-0 ones
-                row += ["@l" + " ".join("%g:%d" % (i, counter[i]) for i in sorted(counter))]
+                items, inv = np.unique(d, return_inverse=True)
+                freq = np.bincount(inv)
+                row += ["@l" + " ".join("%g:%d" % (i, f) for i, f in zip(items, freq))]
         except Exception as e:
             verbose(2, "Failed to obtain stats/counts -- %s" % str(e))
             row += ['error']

nibabel/tests/test_scripts.py

@@ -117,9 +117,9 @@ def test_nib_ls_multiple():
     assert_equal(
         [l[l.index('['):] for l in stdout_lines],
         [
-            '[128,  96,  24,   2] 2.00x2.00x2.20x2000.00  #exts: 2 sform [229725]  [2, 1.2e+03]',
-            '[ 32,  20,  12,   2] 2.00x2.00x2.20x2000.00  #exts: 2 sform  [15360] [46, 7.6e+02]',
-            '[ 18,  28,  29]      9.00x8.00x7.00                          [14616]   [0.12, 93]',
+            '[128,  96,  24,   2] 2.00x2.00x2.20x2000.00  #exts: 2 sform [229725] [2, 1.2e+03]',
+            '[ 32,  20,  12,   2] 2.00x2.00x2.20x2000.00  #exts: 2 sform [15360]  [46, 7.6e+02]',
+            '[ 18,  28,  29]      9.00x8.00x7.00                         [14616]  [0.12, 93]',
             '[ 91, 109,  91]      2.00x2.00x2.00                           error'
         ]
     )