Fix blank line skipping in read_fwf, issue 22693

doc/source/whatsnew/v0.24.0.txt

@@ -767,6 +767,7 @@ I/O
 - :func:`read_sas()` will correctly parse sas7bdat files with data page types having also bit 7 set (so page type is 128 + 256 = 384) (:issue:`16615`)
 - Bug in :meth:`detect_client_encoding` where potential ``IOError`` goes unhandled when importing in a mod_wsgi process due to restricted access to stdout. (:issue:`21552`)
 - Bug in :func:`to_string()` that broke column alignment when ``index=False`` and width of first column's values is greater than the width of first column's header (:issue:`16839`, :issue:`13032`)
+- Fix :func:`read_fwf()` so that empty lines are skipped when the relevant argument is set (:issue:`22693`)
 
 Plotting
 ^^^^^^^^

pandas/io/parsers.py

@@ -3468,3 +3468,22 @@ def __init__(self, f, **kwds):
     def _make_reader(self, f):
         self.data = FixedWidthReader(f, self.colspecs, self.delimiter,
                                      self.comment, self.skiprows)
+
+    def _remove_empty_lines(self, lines):
+        ret = []
+        for l in lines:
+            # Remove blank lines if they're not headers of the
+            # form ['', '', ... ]
+            if not self.line_pos == 0\
+                    and ''.join([str(x) for x in l]).strip() != '':
+                ret.append(l)
+            # Remove header lines that are empty or with only one
+            # whitespace value
+            elif self.line_pos == 0 \
+                    and (
+                        len(l) > 1 or len(l) == 1
+                        and (not isinstance(l[0],
+                             compat.string_types) or l[0].strip())
+                    ):
+                ret.append(l)
+        return ret

pandas/tests/io/parser/test_read_fwf.py

@@ -434,3 +434,13 @@ def test_default_delimiter(self):
                           header=None, skiprows=[0])
 
         tm.assert_frame_equal(result, expected)
+
+    def test_skip_blanklines(self):
+        data_expected = '''A,B
+
+C,D'''
+        expected = read_csv(StringIO(data_expected),
+                            header=None, skip_blank_lines=True)
+        result = read_fwf(StringIO(data_expected), colspecs=[(0, 1), (2, 3)],
+                          header=None, skip_blank_lines=True)
+        tm.assert_frame_equal(result, expected)