fixed problems noted by Travis CI

Author: chrispycheng

nibabel/cmdline/diff.py

@@ -101,10 +101,10 @@ def diff_header_fields(key, inputs):
 
 
 def get_headers_diff(files, opts):
-    """ 
+    """
         Getting the difference of headers.
         Returns a dictionary that is later processed.
-        
+
         Parameters
         ----------
             files: list of files
@@ -113,7 +113,7 @@ def get_headers_diff(files, opts):
 
     header_list = [nib.load(f).header for f in files]
 
-    if opts.header_fields: # will almost always have a header field
+    if opts.header_fields:  # will almost always have a header field
         # signals "all fields"
         if opts.header_fields == 'all':
             # TODO: header fields might vary across file types, thus prior sensing would be needed
@@ -134,19 +134,17 @@ def get_headers_diff(files, opts):
         return {}
 
 
-def get_data_diff(files):
+def get_data_md5sums(files):
 
-    data_list = [nib.load(f).get_data() for f in files]
-    output = []
+    md5sums = [
+        hashlib.md5(np.ascontiguousarray(nib.load(f).get_data(), dtype=np.float32)).hexdigest()
+        for f in files
+    ]
 
-    for a, b in itertools.combinations(data_list, 2):
-        if diff_values(hash(str(a)), hash(str(b))):
-            if hash(str(a)) not in output:
-                output.append(str(hash(str(a))))
-            if hash(str(b)) not in output:
-                output.append(str(hash(str(b))))
+    if len(set(md5sums)) == 1:
+        return []
 
-    return output
+    return md5sums
 
 
 def main():
@@ -164,7 +162,7 @@ def main():
         nib.imageglobals.logger.level = 50
 
     header_diff = get_headers_diff(files, opts)
-    data_diff = get_data_diff(files)
+    data_diff = get_data_md5sums(files)
 
     if len(data_diff) != 0 and len(header_diff) != 0:
         print("{:<11}".format('Field'), end="")

nibabel/tests/test_scripts.py

@@ -72,6 +72,8 @@ def check_nib_diff_examples(opts=[], hdrs_str="", other_str=""):
               for f in ('example4d.nii.gz', 'standard.nii.gz')]
     fnames2 = [pjoin(DATA_PATH, f)
               for f in ('example4d.nii.gz', 'example4d.nii.gz')]
+    hash1 = str(hash(fnames[0]))
+    hash2 = str(hash(fnames[1]))
     code, stdout, stderr = run_command(['nib-diff'] + fnames, check_code=False)
     assert_equal(stdout, "Field      " + "{:<45}".format("example4d.nii.gz") + "{:<45}".format("standard.nii.gz")
                                     + "\n" + "regular    b'r'                                         b''              "
@@ -109,11 +111,11 @@ def check_nib_diff_examples(opts=[], hdrs_str="", other_str=""):
                           "          " + "\n" + "srow_y     [-6.7147157e-19, 1.9737115, -0.35552824, -35.722942][0.0, 3"
                                                 ".0, 0.0, 0.0]                         " + "\n" +
                  "srow_z     [8.2554809e-18, 0.32320762, 2.1710818, -7.2487984][0.0, 0.0, 2.0, 0.0]                    "
-                 "     " + "\n" + "DATA: These files are different.")
+                 "     " + "\n" + "DATA: These files are different.\nChecksum   b0abbc49                    "
+                 + "                 0a2576dd")
 
     code, stdout, stderr = run_command(['nib-diff'] + fnames2, check_code=False)
-    assert_equal(stdout, "Field      "+ "{:<45}".format("example4d.nii.gz") + "{:<45}".format("example4d.nii.gz")
-                         + "\n" + "DATA: These files are identical!")
+    assert_equal(stdout, "DATA: These files are identical!")