Merge pull request #3 from nirum/contextmanager

Creates a contextmanager for live updating of tables

README.md

@@ -49,6 +49,7 @@ Hosted at Read The Docs: [tableprint.readthedocs.org](http://tableprint.readthed
 - `six`
 
 ## Version
+- 0.7.0 (May 26 2017) Adds a TableContext context manager for easy creation of dynamic tables (tables that update periodically). Adds the ability to pass a list or tuple of widths to specify different widths for different columns
 - 0.6.9 (May 25 2017) Splitting the tableprint.py module into a pacakge with multiple files
 - 0.6.7 (May 25 2017) Fixes some bugs with ANSI escape sequences
 - 0.5.0 (Sept 29 2016) Better handling of ANSI escape sequences in table rows

tableprint/metadata.py

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 
 # Version info
-__version__ = '0.6.9'
+__version__ = '0.7.0'
 __license__ = 'MIT'
 
 # Project description(s)

tableprint/printer.py

@@ -21,13 +21,56 @@ from six import string_types
 from .style import LineStyle, STYLES
 from .utils import ansi_len, format_line, parse_width
 
-__all__ = ('table', 'header', 'row', 'hrule', 'top', 'bottom', 'banner', 'dataframe')
+__all__ = ('table', 'header', 'row', 'hrule', 'top', 'bottom', 'banner', 'dataframe', 'TableContext')
 
 STYLE = 'round'
 WIDTH = 11
 FMT = '5g'
 
 
+class TableContext:
+    def __init__(self, headers, width=WIDTH, style=STYLE, add_hr=True, out=sys.stdout):
+        """Context manager for table printing
+
+        Parameters
+        ----------
+        headers : array_like
+            A list of N strings consisting of the header of each of the N columns
+
+        width : int or array_like, optional
+            The width of each column in the table (Default: 11)
+
+        style : string or tuple, optional
+            A formatting style. (Default: 'round')
+
+        add_hr : boolean, optional
+            Whether or not to add a horizontal rule (hr) after the headers
+
+        Usage
+        -----
+        >>> with TableContext("ABC") as t:
+                for k in range(10):
+                    t.row(np.random.randn(3))
+        """
+        self.out = out
+        self.config = {'width': width, 'style': style}
+        self.headers = header(headers, add_hr=add_hr, **self.config)
+        self.bottom = bottom(len(headers), **self.config)
+
+    def __call__(self, data):
+        self.out.write(row(data, **self.config) + '\n')
+        self.out.flush()
+
+    def __enter__(self):
+        self.out.write(self.headers + '\n')
+        self.out.flush()
+        return self
+
+    def __exit__(self, *exc):
+        self.out.write(self.bottom + '\n')
+        self.out.flush()
+
+
 def table(data, headers=None, format_spec=FMT, width=WIDTH, style=STYLE, out=sys.stdout):
     """Print a table with the given data
 

tests/test_io.py

@@ -1,12 +1,21 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
-from tableprint import table, banner, dataframe, hrule
+from tableprint import table, banner, dataframe, hrule, TableContext
 from io import StringIO
 import numpy as np
 
 
-def test_table():
+def test_context():
+    """Tests the table context manager"""
+    output = StringIO()
+    with TableContext('ABC', style='round', width=5, out=output) as t:
+        t([1, 2, 3])
+        t([4, 5, 6])
+    assert output.getvalue() == '╭─────┬─────┬─────╮\n│  A  │  B  │  C  │\n├─────┼─────┼─────┤\n│    1│    2│    3│\n│    4│    5│    6│\n╰─────┴─────┴─────╯\n'
 
+
+def test_table():
+    """Tests the table function"""
     output = StringIO()
     table([[1, 2, 3], [4, 5, 6]], 'ABC', style='round', width=5, out=output)
     assert output.getvalue() == '╭─────┬─────┬─────╮\n│  A  │  B  │  C  │\n├─────┼─────┼─────┤\n│    1│    2│    3│\n│    4│    5│    6│\n╰─────┴─────┴─────╯\n'
@@ -17,7 +26,7 @@ def test_table():
 
 
 def test_frame():
-
+    """Tests the dataframe function"""
     # mock of a pandas DataFrame
     class DataFrame:
         def __init__(self, data, headers):
@@ -35,7 +44,7 @@ def test_frame():
 
 
 def test_banner():
-
+    """Tests the banner function"""
     output = StringIO()
     banner('hello world', style='clean', width=11, out=output)
     assert output.getvalue() == ' ─────────── \n hello world \n ─────────── \n'
@@ -46,7 +55,7 @@ def test_banner():
 
 
 def test_hrule():
-
+    """Tests the hrule function"""
     output = hrule(1, width=11)
     assert len(output) == 11
     assert '───────────'