printio

printio is a MIT licensed pretty printing library implemented in Python.

Format a value(s) for printing or display using Python's built-in String Format library.

Most of the string formatting options from the Format Specification Mini-Language are available. See the formatting options here:

http://docs.python.org/release/3.1.2/library/string.html#format-specification-mini-language

Features

• Align values to the left, right, or center.
• Pad and fill values.
• Sign numerical values.
• Convert integers to float.
• Specify precision for floating values - values are rounded up.
• Convert numbers to percentage formats. Ex. 0.10 ~ 10.0000%
• Add column headers or utilize default headers for your values.
• Column widths are automatically sized based on maximum width of the values.
• Choose which columns to format in your values.
• Ability to print to 'text' similar to how MySQL displays output to the console.

Overview

The major functions of printio:

• PrettyValue():

  Formats a single value to a string.

• PrettyValues():

  Formats a list of lists or dicts.

  • format: will return a list of strings including the header.
  • text: will return a string similar to MySQL's console display format.

License

Made available under the MIT License.

Usage

First, some housekeeping items...

Import the library

>>> from printio import PrettyValue
>>> from printio import PrettyValues

Create a list of values you wish to format.

>>> lol = []
>>> lol.append([0, 'yhoo', 23.45])
>>> lol.append([1, 'goog', 200.4565])
>>> lol.append([2, 't', 1.00])

Let's also create a list of dictionaries to format as well.

>>> keys = ['bar', 'symbol', 'close']
>>> lod = [dict(zip(keys, x)) for x in lol]

Now, let's get down to business...

Format a string with a width of 10, center-aligned, and filled with '-'.

>>> value = 'yhoo'
>>> pv = PrettyValue('^10', fill='-')
>>> pv.format(value)
---yhoo---

Format a float with a decimal precision of 1.

>>> value = 23.45599
>>> pv = PrettyValue('.1f')
>>> pv.format(value)
'23.5'

Format a float into a percentage.

>>> value = 0.025
>>> pv = PrettyValue('.2%')
>>> pv.format(value)
'2.50%'

Format a list.

>>> pv = PrettyValues()
>>> for row in pv.format([lol[0]]): print row
['0', '1   ', '2    ']
['0', 'yhoo', '23.45']

Format a dict.

>>> pv = PrettyValues()
>>> pv.newcol('bar')
>>> pv.newcol('symbol')
>>> pv.newcol('close')
>>> for row in pv.format([lod[0]]): print row
['bar', 'symbol', 'close']
['0  ', 'yhoo  ', '23.45']

Format a list of lists.

>>> pv = PrettyValues()
>>> for row in pv.format(lol): print row
['0', '1   ', '2       ']
['0', 'yhoo', '23.45   ']
['1', 'goog', '200.4565']
['2', 't   ', '1.0     ']

Same as above but this time in text.

>>> pv = PrettyValues()
>>> results = pv.text(lol)
>>> print results
+---+------+----------+
| 0 | 1    | 2        |
+---+------+----------+
| 0 | yhoo | 23.45    |
| 1 | goog | 200.4565 |
| 2 | t    | 1.0      |
+---+------+----------+

Want to add better column names?

>>> pv.newcol(0, cname='Bar')
>>> pv.newcol(1, cname='Symbol')
>>> pv.newcol(2, cname='Close')
>>> print pv.text(lol)
+-----+--------+----------+
| Bar | Symbol | Close    |
+-----+--------+----------+
| 0   | yhoo   | 23.45    |
| 1   | goog   | 200.4565 |
| 2   | t      | 1.0      |
+-----+--------+----------+

Print only the Close column, always show sign, and format with decimal precision of 2.

>>> pv = PrettyValues()
>>> pv.newcol(2, '+.2f', cname='Close')
>>> print pv.text(lol)
+---------+
| Close   |
+---------+
| + 23.45 |
| +200.46 |
| +  1.00 |
+---------+

Print list of dictionaries with the numerical settings for the bar & close.

>>> pv = PrettyValues()
>>> pv.newcol('bar', 'i')
>>> pv.newcol('symbol')
>>> pv.newcol('close', '.2f')
>>> print pv.text(lod)
+-----+--------+--------+
| bar | symbol | close  |
+-----+--------+--------+
|   0 | yhoo   |  23.45 |
|   1 | goog   | 200.46 |
|   2 | t      |   1.00 |
+-----+--------+--------+

Roadmap

• Add option to display title in addition to column headings.
• Add autonum column ability.
• Add tb_html to format to a html table.
• Add pre_html to format <pre> html </pre>.

For additional information, please email:

mike@taylortree.com