ENH: Simplify table2string implementation

nibabel/cmdline/tests/test_utils.py

@@ -28,17 +28,37 @@
 
 
 def test_table2string():
-    assert table2string([['A', 'B', 'C', 'D'], ['E', 'F', 'G', 'H']]) == 'A B C D\nE F G H\n'
+    # Trivial case should do something sensible
+    assert table2string([]) == '\n'
     assert (
         table2string(
-            [
-                ["Let's", 'Make', 'Tests', 'And'],
-                ['Have', 'Lots', 'Of', 'Fun'],
-                ['With', 'Python', 'Guys', '!'],
-            ]
+            [['A', 'B', 'C', 'D'],
+             ['E', 'F', 'G', 'H']]
+        ) == (
+            'A B C D\n'
+            'E F G H\n'
         )
-        == "Let's  Make  Tests And\n Have  Lots    Of  Fun" + '\n With Python  Guys  !\n'
-    )
+    )  # fmt: skip
+    assert (
+        table2string(
+            [["Let's", 'Make', 'Tests', 'And'],
+             ['Have', 'Lots', 'Of', 'Fun'],
+             ['With', 'Python', 'Guys', '!']]
+        ) == (
+            "Let's  Make  Tests And\n"
+            'Have   Lots   Of   Fun\n'
+            'With  Python Guys   !\n'
+        )
+    )  # fmt: skip
+    assert (
+        table2string(
+            [['This', 'Table', '@lIs', 'Ragged'],
+             ['And', '@rit', 'uses', '@csome', 'alignment', 'markup']]
+        ) == (
+            'This Table Is   Ragged\n'
+            'And     it uses  some  alignment markup\n'
+        )
+    )  # fmt: skip
 
 
 def test_ap():

nibabel/cmdline/utils.py

@@ -12,10 +12,6 @@
 
 # global verbosity switch
 import re
-from io import StringIO
-from math import ceil
-
-import numpy as np
 
 verbose_level = 0
 
@@ -42,32 +38,28 @@
     table : list of lists of strings
       What is aimed to be printed
     out : None or stream
-      Where to print. If None -- will print and return string
+      Where to print. If None, return string
 
     Returns
     -------
     string if out was None
     """
 
-    print2string = out is None
-    if print2string:
-        out = StringIO()
-
     # equalize number of elements in each row
     nelements_max = len(table) and max(len(x) for x in table)
 
+    table = [row + [''] * (nelements_max - len(row)) for row in table]
     for i, table_ in enumerate(table):
         table[i] += [''] * (nelements_max - len(table_))
 
-    # figure out lengths within each column
-    atable = np.asarray(table)
     # eat whole entry while computing width for @w (for wide)
     markup_strip = re.compile('^@([lrc]|w.*)')
-    col_width = [max(len(markup_strip.sub('', x)) for x in column) for column in atable.T]
-    string = ''
-    for i, table_ in enumerate(table):
-        string_ = ''
-        for j, item in enumerate(table_):
+    col_width = [max(len(markup_strip.sub('', x)) for x in column) for column in zip(*table)]
+    trans = str.maketrans("lrcw", "<>^^")
+    lines = []
+    for row in table:
+        line = []
+        for item, width in zip(row, col_width):
             item = str(item)
             if item.startswith('@'):
                 align = item[1]
@@ -77,26 +69,14 @@
             else:
                 align = 'c'
 
-            nspacesl = max(ceil((col_width[j] - len(item)) / 2.0), 0)
-            nspacesr = max(col_width[j] - nspacesl - len(item), 0)
-
-            if align in ('w', 'c'):
-                pass
-            elif align == 'l':
-                nspacesl, nspacesr = 0, nspacesl + nspacesr
-            elif align == 'r':
-                nspacesl, nspacesr = nspacesl + nspacesr, 0
-            else:
-                raise RuntimeError(f'Should not get here with align={align}')
-
-            string_ += '%%%ds%%s%%%ds ' % (nspacesl, nspacesr) % ('', item, '')
-        string += string_.rstrip() + '\n'
-    out.write(string)
+            line.append(f'{item:{align.translate(trans)}{width}}')
+        lines.append(' '.join(line).rstrip())
 
-    if print2string:
-        value = out.getvalue()
-        out.close()
-        return value
+    ret = '\n'.join(lines) + '\n'
+    if out is not None:
+        out.write(ret)
+    else:
+        return ret
 
 
 def ap(helplist, format_, sep=', '):