qanda 0.1dev

Simple text prompts and validation for user input

Background

Interactive command-line programs need to query users for information, be it text, choices from a list, or simple yes-or-no answers. qanda is a Python module of simple functions to prompt users for such information, allowing validation and cleanup of answers, default responses, consistent formatting and presentation of help text, hints and choices. It is not a replacement for textual interfaces like curses and urwid, but intended solely for simple console scripts with user input is required.

Installation

The simplest way to install qanda is via easy_install or an equivalent program:

% easy_install qanda

Alternatively the tarball can be downloaded, unpacked and setup.py run:

% tar zxvf qanda.tgz
% cd qanda
% python set.py install

qanda has no requisites and should work with just about any version of Python.

Using qanda

Examples

>>> from qanda import prompt
>>> prompt.string ("What is your name")
What is your name: Foo
>>> fname = prompt.string ("Your friends name is",
                help="I need to know your friends name as well before I talk to you.",
                hints="first name",
                default='Bar',
        )

I need to know your friends name as well before I talk to you.
Your friends name is (first name) [Bar]:
>>> print fname
Bar
>>> years = prompt.integer ("And what is your age", min=1, max=100)
And what is your age: 101
A problem: 101 is higher than 100. Try again ...
And what is your age: 28

Central concepts

qanda packages all question-asking methods in a Session class. This allows the appearance and functioning of all these methods to be handled consistently and modified centrally. However, you don’t necessarily have to create a Session to use it - there’s pre-existing Session in the variable called prompt:

>>> from qanda import Session
>>> s = Session()
>>> from qanda import prompt
>>> type (prompt)
<class 'qanda.session.Session'>

The question methods are named after the type of data they elicit:

>>> print type(prompt.integer ("Pick a number"))
Pick a number: 2
<type 'int'>
>>> print type(prompt.string ("Pick a name"))
Pick a name: Bob
<type 'string'>

Many of the question methods with accept a list of “converters”, each of which is used to sucessively transform or validate user input. If input fails validation, the question is posed again. qanda supplies a number of basic validators:

ToInt, ToFloat

Convert inputs to other types

Regex

nly allow values that match a certain pattern

Range

Check that input falls within given bounds

Length

Check that input length falls within given bounds

Synonyms

Map values to other values

Vocab

Ensure values fall within a fixed set

References

[qanda-home]

qanda home page http://www.agapow.net/software/py-qanda

[qanda-pypi]

qanda on PyPi

History

v0.1dev (20110624)

• Initial release, sure to be buggy and incomplete