Merge 1397efb into b8068f8

docs/changes.rst

@@ -1,6 +1,13 @@
 Changes
 =======
 
+Version 1.6.9
+-------------
+
+* Added `toxml()` as convenience wrapper over `totext()`.
+  By :user:`juarezr`, :issue:`529`.
+
+
 Version 1.6.8
 -------------
 

docs/io.rst

@@ -108,8 +108,6 @@ XML files
 
 .. autofunction:: petl.io.xml.fromxml
 
-For writing to an XML file, see :func:`petl.io.text.totext`.
-
 
 .. module:: petl.io.html
 .. _io_html:

petl/io/__init__.py

@@ -13,7 +13,7 @@
 
 from petl.io.text import fromtext, totext, appendtext, teetext
 
-from petl.io.xml import fromxml
+from petl.io.xml import fromxml, toxml
 
 from petl.io.html import tohtml, teehtml
 

petl/io/xml.py

@@ -15,8 +15,9 @@
 
 
 # internal dependencies
-from petl.util.base import Table
+from petl.util.base import Table, fieldnames, iterpeek
 from petl.io.sources import read_source_from_arg
+from petl.io.text import totext
 
 
 def fromxml(source, *args, **kwargs):
@@ -260,3 +261,106 @@ def _get(v):
         else:
             return missing
     return _get
+
+
+def toxml(table, filename=None, 
+          root=None, head=None, rows=None, 
+          prologue=None, epilogue=None, encoding='utf-8'):
+    """
+    Write the table to a xml file. E.g.::
+
+        >>> import petl as etl
+        >>> table1 = [['foo', 'bar'],
+        ...           ['a', 1],
+        ...           ['b', 2],
+        ...           ['c', 3]]
+        >>> etl.toxml(table1, 'example4.xml')
+        >>> # see what we did
+        ... print(open('example4.xml').read())
+        <?xml version="1.0" encoding="UTF-8"?>
+        <table><thead>
+         <tr><th>foo</th><th>bar</th></tr>
+        </thead><tbody>
+         <tr><td>a</td><td>1</td></tr>
+         <tr><td>b</td><td>2</td></tr>
+         <tr><td>c</td><td>3</td></tr>
+        </tbody></table>
+        >>> etl.toxml(table1, 'example5.xml', rows='plan/line/cell')
+        >>> print(open('example5.xml').read())
+        <?xml version="1.0" encoding="UTF-8"?>
+        <plan>
+         <line><cell>a</cell><cell>1</cell></line>
+         <line><cell>b</cell><cell>2</cell></line>
+         <line><cell>c</cell><cell>3</cell></line>
+        </plan>
+
+    The `toxml()` function is just a wrapper over :func:`petl.io.text.totext`.
+    For advanced casees use a template with `totext()`.
+
+    """
+    if not root and not head and not rows:
+        root = 'table'
+        head = 'thead/tr/th'
+        rows = 'tbody/tr/td'
+
+    sample, table2 = iterpeek(table, 2)
+    props = fieldnames(sample)
+
+    top = _build_xml_header(props, root, head, rows, prologue, encoding)
+    template = _build_cols(props, rows, '{%s}')
+    bottom = _build_xml_footer(epilogue, rows, root)
+
+    totext(table2, source=filename, encoding=encoding, errors='strict',
+           template=template, prologue=top, epilogue=bottom)
+
+
+def _build_xml_header(props, root, head, rows, prologue, encoding):
+    tab = _build_nesting(root, False, None) if root else ''
+    if head:
+        th1 = _build_nesting(head, False, -2)
+        col = _build_cols(props, head, '%s') 
+        th2 = _build_nesting(head, True, -2)
+        thd = '%s\n%s%s' % (th1, col, th2)
+    else:
+        thd = ''
+    tbd = _build_nesting(rows, False, -2)
+    thb = '%s%s%s\n' % (tab, thd, tbd)
+    if prologue and prologue.startswith('<?xml'):
+        return prologue + thb 
+    enc = encoding.upper() if encoding else 'UTF-8'
+    xml = '<?xml version="1.0" encoding="%s"?>' % enc
+    pre = prologue if prologue else ''
+    return '%s\n%s%s' % (xml, pre, thb)
+
+
+def _build_xml_footer(epilogue, rows, root):
+    tbd = _build_nesting(rows, True, -2)
+    tab = _build_nesting(root, True, None)
+    return epilogue + tbd + tab if epilogue else tbd + tab
+
+
+def _build_nesting(path, closing, index):
+    if not path:
+        return ''
+    fmt = '</%s>' if closing else '<%s>'
+    if '/' not in path:
+        return fmt % path
+    parts = path.split('/')
+    elements = parts[0:index] if index else parts
+    if closing:
+        elements.reverse()
+    tags = [fmt % e for e in elements]
+    return ''.join(tags)
+
+
+def _build_cols(props, path, placeholder):
+    if '/' not in path:
+        raise ValueError("Argument must have at least 2 elements for row/col: %s" % path)
+    parts = path.split('/')
+    col = parts[-1]
+    fmt = '<%s>%s</%s>' % (col, placeholder, col)
+    tags = [fmt % e for e in props]
+    cols = ''.join(tags)
+    row = parts[-2:-1][0]
+    res = ' <%s>%s</%s>\n' % (row, cols, row)
+    return res

petl/test/io/test_xml.py

@@ -8,7 +8,7 @@
 
 from petl.test.helpers import ieq
 from petl.util import nrows, look
-from petl.io.xml import fromxml
+from petl.io.xml import fromxml, toxml
 from petl.compat import urlopen
 
 
@@ -305,3 +305,64 @@ def test_fromxml_entity():
         pass
     else:
         assert True, 'Error testing XML'
+
+
+def _check_toxml(table, expected, check=(), **kwargs):
+    with NamedTemporaryFile(delete=True, suffix='.xml') as f:
+        filename = f.name
+    toxml(table, filename, **kwargs)
+    try:
+        actual = fromxml(filename, *check)
+        _compare(expected, actual)
+    except Exception as ex:
+        print('XML:', open(filename).read(), file=sys.stderr)
+        raise ex
+
+
+_HEAD1 = (('foo', 'bar'),)
+_BODY1 = (('a', '1'),
+          ('b', '2'),
+          ('c', '3'))
+_TABLE1 = _HEAD1 + _BODY1
+
+
+def test_toxml1():
+    _check_toxml(
+        _TABLE1, _TABLE1,
+        check=('.//tr', ('th', 'td'))
+    )
+
+
+def test_toxml2():
+    _check_toxml(
+        _TABLE1, _BODY1,
+        check=('.//row', 'col'),
+        root='matrix',
+        rows='row/col'
+    )
+
+
+def test_toxml3():
+    _check_toxml(
+        _TABLE1, _BODY1,
+        check=('line', 'cell'),
+        rows='plan/line/cell'
+    )
+
+
+def test_toxml4():
+    _check_toxml(
+        _TABLE1, _BODY1,
+        check=('.//line', 'cell'),
+        rows='dir/file/book/plan/line/cell'
+    )
+
+
+def test_toxml5():
+    _check_toxml(
+        _TABLE1, _TABLE1,
+        check=('.//x', 'y'),
+        root='a',
+        head='h/k/x/y',
+        rows='r/v/x/y'
+    )

tox.ini

@@ -27,6 +27,10 @@ deps =
     -rtest_requirements.txt
     -roptional_requirements.txt
 
+[testenv:{py36,py37,py38,py39}-doctest]
+commands =
+    py36,py37,py38,py39: nosetests -v --with-doctest --doctest-options=+NORMALIZE_WHITESPACE petl -I"csv_py2\.py" -I"db\.py"
+
 [testenv:{py37,py38,py39}-docs]
 # build documentation under similar environment to readthedocs
 changedir = docs