RF,DOC: Clarify index column position in loadData/loadFile. Small clean up in

fileinfo.

ukbparse/fileinfo.py

@@ -78,7 +78,7 @@ def has_header(sample,
         # match, we take the length of
         # the value, in the hope that the
         # column will have a different
-        # length to the
+        # length to the header row value
         else:
             return len(val)
 
@@ -102,8 +102,9 @@ def has_header(sample,
         for i, col in enumerate(row):
             ct = inferType(col)
 
-            # missing values are
-            # not considered
+            # missing values are treated
+            # like any other value - they
+            # are given a type of "None"
             coltypes[i].append(ct)
 
     # we build a score based on the
@@ -180,7 +181,7 @@ def sniff(datafile):
     sample  = '\n'.join(lines)
 
     try:
-        dialect = sniffer.sniff(sample, ' .,\t:;|/\~!@#$~%^&*')
+        dialect = sniffer.sniff(sample, ' .,\t:;|/\\~!@#$~%^&*')
     except csv.Error:
         dialect = None
 
@@ -223,22 +224,17 @@ def sniff(datafile):
         raise ValueError('Could not determine file format: '
                          '{}'.format(datafile))
 
-    # if whitespace-delimited, we re-generate
-    # the sample into a format that will be
-    # recognised by the sniffer, purely so we
-    # can use its has_header method. We take
-    # a copy of the first row, so we can
-    # extract column names if possible.
-    if dialect == 'whitespace':
-        firstRow  = lines[0].split()
-        hasHeader = has_header('\n'.join(lines), dialect)
+    # Use the has_header function to
+    # figure out if we have column names
+    hasHeader = has_header(sample, dialect)
 
-    # Otherwise we pass the unmodified sample,
-    # and read in the first row.
+    # And take a copy of the first row,
+    # in case we do have column names.
+    if dialect == 'whitespace':
+        firstRow = lines[0].split()
     else:
-        hasHeader = has_header(sample, dialect)
-        reader    = csv.reader(io.StringIO(sample), dialect)
-        firstRow  = next(reader)
+        reader   = csv.reader(io.StringIO(sample), dialect)
+        firstRow = next(reader)
 
     log.debug('Detected dialect for input file %s: (header: %s, '
               'delimiter: %s)',

ukbparse/importing.py

@@ -369,8 +369,11 @@ def columnsToLoad(datafiles,
 
                          - A dict of ``{ file : [Column] }`` mappings, the
                            :class:`.Column` objects to *load* from each input
-                           file. The columns are not necessarily ordered in the
-                           same way that they are in the input files.
+                           file.
+
+                           Note that the columns are not necessarily ordered
+                           in the same way that they are in the input files -
+                           the header column will always be first in each list.
 
                          - A list containing the :class:`.Column` objects to
                            *ignore*.
@@ -545,8 +548,7 @@ def loadData(datafiles,
                            :class:`.HDFStoreCollection`, containing the data,
                            or ``None`` if ``dryrun is True``.
                          - A list of :class:`.Column` objects representing the
-                           columns that were loaded. The index column is placed
-                           at the beginning of this list.
+                           columns that were loaded.
     """
 
     if mergeStrategy is None: mergeStrategy = MERGE_STRATEGY
@@ -651,8 +653,8 @@ def loadFile(fname,
                     in the file.
 
     :arg toload:    Sequence of :class:`.Column` objects describing the columns
-                    that should be loaded. This list is not assumed to be
-                    ordered.
+                    that should be loaded. It is assumed that the first column
+                    in this list is the index column.
 
     :arg index:     Column position of index column (starting from 0). Defaults
                     to 0.