Family Day update

Task/Align-columns/Python/align-columns-1.py

@@ -1,45 +1,19 @@
-from StringIO import StringIO
+from itertools import zip_longest
 
-textinfile = '''Given$a$text$file$of$many$lines,$where$fields$within$a$line$
+txt = """Given$a$txt$file$of$many$lines,$where$fields$within$a$line$
 are$delineated$by$a$single$'dollar'$character,$write$a$program
 that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$
 column$are$separated$by$at$least$one$space.
 Further,$allow$for$each$word$in$a$column$to$be$either$left$
-justified,$right$justified,$or$center$justified$within$its$column.'''
+justified,$right$justified,$or$center$justified$within$its$column."""
 
-j2justifier = dict(L=str.ljust, R=str.rjust, C=str.center)
+parts = [line.rstrip("$").split("$") for line in txt.splitlines()]
+widths = [max(len(word) for word in col)
+          for col in zip_longest(*parts, fillvalue='')]
 
-def aligner(infile, justification = 'L'):
-  ''' \
-  Justify columns of textual tabular input where the row separator is the newline
-  and the field separator is a 'dollar' character.
-  justification can be L, R, or C; (Left, Right, or Centered).
-
-  Return the justified output as a string
-  '''
-  assert justification in j2justifier, "justification can be L, R, or C; (Left, Right, or Centered)."
-  justifier = j2justifier[justification]
-
-  fieldsbyrow= [line.strip().split('$') for line in infile]
-  # pad to same number of fields per row
-  maxfields = max(len(row) for row in fieldsbyrow)
-  fieldsbyrow = [fields + ['']*(maxfields - len(fields))
-                    for fields in fieldsbyrow]
-  # rotate
-  fieldsbycolumn = zip(*fieldsbyrow)
-  # calculate max fieldwidth per column
-  colwidths = [max(len(field) for field in column)
-               for column in fieldsbycolumn]
-  # pad fields in columns to colwidth with spaces
-  fieldsbycolumn = [ [justifier(field, width) for field in column]
-                     for width, column in zip(colwidths, fieldsbycolumn) ]
-  # rotate again
-  fieldsbyrow = zip(*fieldsbycolumn)
-
-  return "\n".join( " ".join(row) for row in fieldsbyrow)
-
-
-for align in 'Left Right Center'.split():
-  infile = StringIO(textinfile)
-  print "\n# %s Column-aligned output:" % align
-  print aligner(infile, align[0])
+for justify in "<_Left ^_Center >_Right".split():
+    j, jtext = justify.split('_')
+    print(f"{jtext} column-aligned output:\n")
+    for line in parts:
+        print(' '.join(f"{wrd:{j}{wdth}}" for wdth, wrd in zip(widths, line)))
+    print("- " * 52)