Merge b3c295b into c411e0f

petl/io/csv_py2.py

@@ -112,7 +112,10 @@ def __iter__(self):
             it = iter(self.table)
 
             # deal with header row
-            hdr = next(it)
+            try:
+                hdr = next(it)
+            except StopIteration:
+                return
             if self.write_header:
                 writer.writerow(hdr)
             # N.B., always yield header, even if we don't write it

petl/io/csv_py3.py

@@ -20,15 +20,15 @@ def fromcsv_impl(source, **kwargs):
 class CSVView(Table):
 
     def __init__(self, source, encoding, errors, header, **csvargs):
-            self.source = source
-            self.encoding = encoding
-            self.errors = errors
-            self.csvargs = csvargs
-            self.header = header
+        self.source = source
+        self.encoding = encoding
+        self.errors = errors
+        self.csvargs = csvargs
+        self.header = header
 
     def __iter__(self):
         if self.header is not None:
-          yield tuple(self.header)
+            yield tuple(self.header)
         with self.source.open('rb') as buf:
             csvfile = io.TextIOWrapper(buf, encoding=self.encoding,
                                        errors=self.errors, newline='')
@@ -86,7 +86,10 @@ def __iter__(self):
             try:
                 writer = csv.writer(csvfile, **self.csvargs)
                 it = iter(self.table)
-                hdr = next(it)
+                try:
+                    hdr = next(it)
+                except StopIteration:
+                    return
                 if self.write_header:
                     writer.writerow(hdr)
                 yield tuple(hdr)

petl/io/html.py

@@ -75,7 +75,10 @@ def tohtml(table, source=None, encoding=None, errors='strict', caption=None,
             it = iter(table)
 
             # write header
-            hdr = next(it)
+            try:
+                hdr = next(it)
+            except StopIteration:
+                hdr = []
             _write_begin(f, hdr, lineterminator, caption, index_header,
                          truncate)
 
@@ -166,10 +169,13 @@ def __iter__(self):
                 it = iter(table)
 
                 # write header
-                hdr = next(it)
+                try:
+                    hdr = next(it)
+                    yield hdr
+                except StopIteration:
+                    hdr = []
                 _write_begin(f, hdr, lineterminator, caption, index_header,
                              truncate)
-                yield hdr
 
                 # write body
                 if tr_style and callable(tr_style):
@@ -193,16 +199,17 @@ def _write_begin(f, flds, lineterminator, caption, index_header, truncate):
     f.write("<table class='petl'>" + lineterminator)
     if caption is not None:
         f.write(('<caption>%s</caption>' % caption) + lineterminator)
-    f.write('<thead>' + lineterminator)
-    f.write('<tr>' + lineterminator)
-    for i, h in enumerate(flds):
-        if index_header:
-            h = '%s|%s' % (i, h)
-        if truncate:
-            h = h[:truncate]
-        f.write(('<th>%s</th>' % h) + lineterminator)
-    f.write('</tr>' + lineterminator)
-    f.write('</thead>' + lineterminator)
+    if flds:
+        f.write('<thead>' + lineterminator)
+        f.write('<tr>' + lineterminator)
+        for i, h in enumerate(flds):
+            if index_header:
+                h = '%s|%s' % (i, h)
+            if truncate:
+                h = h[:truncate]
+            f.write(('<th>%s</th>' % h) + lineterminator)
+        f.write('</tr>' + lineterminator)
+        f.write('</thead>' + lineterminator)
     f.write('<tbody>' + lineterminator)
 
 

petl/io/pandas.py

@@ -29,7 +29,10 @@ def todataframe(table, index=None, exclude=None, columns=None,
     """
     import pandas as pd
     it = iter(table)
-    header = next(it)
+    try:
+        header = next(it)
+    except StopIteration:
+        header = None  # Will create an Empty DataFrame
     if columns is None:
         columns = header
     return pd.DataFrame.from_records(it, index=index, exclude=exclude,

petl/io/pickle.py

@@ -119,7 +119,10 @@ def _writepickle(table, source, mode, protocol, write_header):
     source = write_source_from_arg(source, mode)
     with source.open(mode) as f:
         it = iter(table)
-        hdr = next(it)
+        try:
+            hdr = next(it)
+        except StopIteration:
+            return
         if write_header:
             pickle.dump(hdr, f, protocol)
         for row in it:
@@ -153,7 +156,10 @@ def __iter__(self):
         source = write_source_from_arg(self.source)
         with source.open('wb') as f:
             it = iter(self.table)
-            hdr = next(it)
+            try:
+                hdr = next(it)
+            except StopIteration:
+                return
             if self.write_header:
                 pickle.dump(hdr, f, protocol)
             yield tuple(hdr)

petl/io/text.py

@@ -194,7 +194,10 @@ def _writetext(table, source, mode, encoding, errors, template, prologue,
             if prologue is not None:
                 f.write(prologue)
             it = iter(table)
-            hdr = next(it)
+            try:
+                hdr = next(it)
+            except StopIteration:
+                hdr = []
             flds = list(map(text_type, hdr))
             for row in it:
                 rec = asdict(flds, row)
@@ -266,7 +269,10 @@ def _iterteetext(table, source, encoding, errors, template, prologue, epilogue):
             if prologue is not None:
                 f.write(prologue)
             it = iter(table)
-            hdr = next(it)
+            try:
+                hdr = next(it)
+            except StopIteration:
+                return
             yield tuple(hdr)
             flds = list(map(text_type, hdr))
             for row in it:

petl/io/xls.py

@@ -85,12 +85,15 @@ def toxls(tbl, filename, sheet, encoding=None, style_compression=0,
     else:
         # handle styles
         it = iter(tbl)
-        hdr = next(it)
-        flds = list(map(str, hdr))
-        for c, f in enumerate(flds):
-            ws.write(0, c, label=f)
-            if f not in styles or styles[f] is None:
-                styles[f] = xlwt.Style.default_style
+        try:
+            hdr = next(it)
+            flds = list(map(str, hdr))
+            for c, f in enumerate(flds):
+                ws.write(0, c, label=f)
+                if f not in styles or styles[f] is None:
+                    styles[f] = xlwt.Style.default_style
+        except StopIteration:
+            pass  # no header written
         # convert to list for easy zipping
         styles = [styles[f] for f in flds]
         for r, row in enumerate(it):

petl/io/xlsx.py

@@ -113,9 +113,12 @@ def toxlsx(tbl, filename, sheet=None, write_header=True, mode="replace"):
     ws = _insert_sheet_on_workbook(mode, sheet, wb)
     if write_header:
         it = iter(tbl)
-        hdr = next(it)
-        flds = list(map(text_type, hdr))
-        rows = itertools.chain([flds], it)
+        try:
+            hdr = next(it)
+            flds = list(map(text_type, hdr))
+            rows = itertools.chain([flds], it)
+        except StopIteration:
+            rows = it
     else:
         rows = data(tbl)
     for row in rows:
@@ -184,9 +187,12 @@ def appendxlsx(tbl, filename, sheet=None, write_header=False):
             ws = wb[str(sheet)]
         if write_header:
             it = iter(tbl)
-            hdr = next(it)
-            flds = list(map(text_type, hdr))
-            rows = itertools.chain([flds], it)
+            try:
+                hdr = next(it)
+                flds = list(map(text_type, hdr))
+                rows = itertools.chain([flds], it)
+            except StopIteration:
+                rows = it
         else:
             rows = data(tbl)
         for row in rows:

petl/test/helpers.py

@@ -10,7 +10,7 @@
 
 def eq_(expect, actual, msg=None):
     """Test when two values from a python variable are exactly equals (==)"""
-    assert expect == actual, msg
+    assert expect == actual, msg or ('%r != %s' % (expect, actual))
 
 
 def assert_almost_equal(first, second, places=None, msg=None):

petl/test/io/test_html.py

@@ -118,3 +118,21 @@ def test_tohtml_with_style():
             u"</table>\n"
         )
         eq_(expect, actual)
+
+
+def test_tohtml_headerless():
+    table = []
+
+    f = NamedTemporaryFile(delete=False)
+    tohtml(table, f.name, encoding='ascii', lineterminator='\n')
+
+    # check what it did
+    with io.open(f.name, mode='rt', encoding='ascii', newline='') as o:
+        actual = o.read()
+        expect = (
+            u"<table class='petl'>\n"
+            u"<tbody>\n"
+            u"</tbody>\n"
+            u"</table>\n"
+        )
+        eq_(expect, actual)

petl/test/io/test_pandas.py

@@ -26,6 +26,12 @@ def test_todataframe():
         actual = todataframe(tbl)
         assert expect.equals(actual)
 
+    def test_headerless():
+        tbl = []
+        expect = pd.DataFrame()
+        actual = todataframe(tbl)
+        assert expect.equals(actual)
+
     def test_fromdataframe():
         tbl = [('foo', 'bar', 'baz'),
                ('apples', 1, 2.5),

petl/test/io/test_pickle.py

@@ -10,6 +10,14 @@
 from petl.io.pickle import frompickle, topickle, appendpickle
 
 
+def picklereader(fl):
+    try:
+        while True:
+            yield pickle.load(fl)
+    except EOFError:
+        pass
+
+
 def test_frompickle():
 
     f = NamedTemporaryFile(delete=False)
@@ -36,13 +44,6 @@ def test_topickle_appendpickle():
     f = NamedTemporaryFile(delete=False)
     topickle(table, f.name)
 
-    def picklereader(fl):
-        try:
-            while True:
-                yield pickle.load(fl)
-        except EOFError:
-            pass
-
     # check what it did
     with open(f.name, 'rb') as o:
         actual = picklereader(o)
@@ -66,3 +67,12 @@ def picklereader(fl):
                   ('e', 9),
                   ('f', 1))
         ieq(expect, actual)
+
+
+def test_topickle_headerless():
+    table = []
+    f = NamedTemporaryFile(delete=False)
+    topickle(table, f.name)
+    expect = []
+    with open(f.name, 'rb') as o:
+        ieq(expect, picklereader(o))

petl/test/io/test_text.py

@@ -174,3 +174,18 @@ def test_totext_gz():
         eq_(expect, actual)
     finally:
         o.close()
+
+
+def test_totext_headerless():
+    table = []
+    f = NamedTemporaryFile(delete=False)
+    prologue = "-- START\n"
+    template = "+ {f1}\n"
+    epilogue = "-- END\n"
+    totext(table, f.name, encoding='ascii', template=template,
+           prologue=prologue, epilogue=epilogue)
+
+    with io.open(f.name, mode='rt', encoding='ascii', newline='') as o:
+        actual = o.read()
+        expect = prologue + epilogue
+        eq_(expect, actual)

petl/test/io/test_xls.py

@@ -85,6 +85,15 @@ def test_toxls():
         ieq(expect, actual)
         ieq(expect, actual)
 
+    def test_toxls_headerless():
+        expect = []
+        f = NamedTemporaryFile(delete=False)
+        f.close()
+        toxls(expect, f.name, 'Sheet1')
+        actual = fromxls(f.name, 'Sheet1')
+        ieq(expect, actual)
+        ieq(expect, actual)
+
     def test_toxls_date():
         expect = (('foo', 'bar'),
                   (u'é', datetime(2012, 1, 1)),
@@ -128,4 +137,4 @@ def wrapper(self, *args, **kwargs):
                       ('C', 2),
                       (u'é', datetime(2012, 1, 1)))
             ieq(expect, tbl)
-            ieq(expect, tbl)
+            ieq(expect, tbl)

petl/test/io/test_xlsx.py

@@ -226,3 +226,13 @@ def test_appendxlsx_with_non_str_header(xlsx_table_with_non_str_header, xlsx_tes
     appendxlsx(xlsx_table_with_non_str_header, f.name, 'Sheet1')
     expect = etl.cat(xlsx_test_table, xlsx_table_with_non_str_header)
     ieq(expect, actual)
+
+
+def test_toxlsx_headerless():
+    expect = []
+    f = NamedTemporaryFile(delete=False)
+    f.close()
+    toxlsx(expect, f.name)
+    actual = fromxlsx(f.name)
+    ieq(expect, actual)
+    ieq(expect, actual)