Add methods for simpler newlines (#246)

src/escpos/escpos.py

@@ -460,6 +460,28 @@ class Escpos(object):
         txt = six.text_type(txt)
         self.magic.write(txt)
 
+    def textln(self, txt=''):
+        """Print alpha-numeric text with a newline
+
+        The text has to be encoded in the currently selected codepage.
+        The input text has to be encoded in unicode.
+
+        :param txt: text to be printed with a newline
+        :raises: :py:exc:`~escpos.exceptions.TextError`
+        """
+        self.text('{}\n'.format(txt))
+
+    def ln(self, count=1):
+        """Print a newline or more
+
+        :param count: number of newlines to print
+        :raises: :py:exc:`ValueError` if count < 0
+        """
+        if count < 0:
+            raise ValueError('Count cannot be lesser than 0')
+        if count > 0:
+            self.text('\n' * count)
+
     def block_text(self, txt, font=None, columns=None):
         """ Text is printed wrapped to specified columns
 

test/test_function_text.py

@@ -39,3 +39,27 @@ def test_block_text():
         "All the presidents men were eating falafel for breakfast.", font='a')
     assert printer.output == \
         b'All the presidents men were eating falafel\nfor breakfast.'
+
+
+def test_textln():
+    printer = get_printer()
+    printer.textln('hello, world')
+    assert printer.output == b'hello, world\n'
+
+
+def test_textln_empty():
+    printer = get_printer()
+    printer.textln()
+    assert printer.output == b'\n'
+
+
+def test_ln():
+    printer = get_printer()
+    printer.ln()
+    assert printer.output == b'\n'
+
+
+def test_multiple_ln():
+    printer = get_printer()
+    printer.ln(3)
+    assert printer.output == b'\n\n\n'