bwo / pyline

Python rewrite/reinterpretation of the Ruby HighLine CLI library

PyLine

PyLine is a Python rewrite/reinterpretation of the Ruby CLI library HighLine.

It supports colored output, user interaction (via simple questions or complex menus), auto-paged, column-wrapped output, and almost no documentation at the moment.

But it does have some examples! Look:

Examples

Colorized text:

>>> p = PyLine(colors=True)
>>> p.say("Hello, {__colors.green.on_blue.bold:{1} world}!", "colorful")
Hello, colorful world! # (but "colorful world" is in bold, green text on a blue background, see. That's the point.)
>>> with p.no_colors():
    p.say("Hello, {__colors.green.on_blue.bold:{1} world}!", "drab")
Hello, drab world! # (not colorized)

Simple questions:

>>> answer = p.agree("Neat, huh? ")
Neat, huh?  (y or n) q
Please answer y, n, yes, or no
Neat, huh?  (y or n) y
>>> answer
True
>>> q = Question(prompt="Enter a sekrit number between 4 and 23 (exclusive): ", answer=IntAnswer(below=23, above=4), echo="*", ask_on_error="do it right: ")
>>> ans = p.ask(q)
Enter a sekrit number between 4 and 23 (exclusive): **
Your answer isn't within the expected range: below 23 and above 4
do it right: *
Your answer isn't within the expected range: below 23 and above 4
do it right: *
>>> ans
9
>>> q = Question(prompt="What's your favorite configuration file? ", answer=Pathname(directory="/etc", glob="*.conf"), default="logrotate.conf")
>>> p.ask(q)
What's your favorite configuration file?  |logrotate.conf|
'/etc/logrotate.conf'
>>> p.ask(q)
What's your favorite configuration file?  |logrotate.conf| n
Ambiguous match: could be any of nscd.conf, nsswitch.conf, or ntp.conf
? nscd
'/etc/nscd.conf'
>>> q = Question("What's your favorite language? ", answer="perl python ruby".split(), confirm=True)
>>> p.ask(q)
What's your favorite language? perl
Are you sure?  (y or n) y
'perl'

More complex questions:

>>> m = Menu(header="another way to choose your fav", prompt="-> ")
>>> m.add_choices("perl python ruby".split(), None)
>>> m.add_hidden(MenuChoice("haskell"))
>>> p.choose(m)
another way to choose your fav:
1. perl
2. python
3. ruby
-> haskell
'haskell'
>>> m.select_by = INDEX
>>> m.layout = MenuOnly()
>>> p.wrap_at = 20
>>> p.choose(m)
1. perl, 2. python,
or 3. ruby
-> 2
'python'
>>> q = Question(prompt="what is your favorite {key}? ", gather=["animal", "color", "food"])
>>> ans = p.ask(q)
what is your favorite animal? bear
what is your favorite color? blue
what is your favorite food? berry
>>> ans
{'color': 'blue', 'food': 'berry', 'animal': 'bear'}

Menus can also act as shells, associating each choice with a function to be called with the rest of the line:

>>> m = Menu(header="perform stupid string tricks", items=[("reverse", lambda opt, mn, line: mn.pyline.say(line[::-1]), "reverse the string"), ("upcase", lambda opt, mn, line: mn.pyline.say(line.upper()), "make the string uppercase"), menu.quit_shell("quit", "quit the shell"), menu.repeat_shell("repeat", "repeat the question")], shell=True)
>>> p.shell(m)
perform stupid string tricks:
1. reverse
2. upcase
3. quit
4. repeat
5. help
? reverse this stuff
ffuts siht
? upcase this other stuff
THIS OTHER STUFF
? help rep
= repeat

repeat the question
? rep
perform stupid string tricks:
1. reverse
2. upcase
3. quit
4. repeat
5. help
? q
>>>

Of course that is not how you would normally populate the menu object.

Lots of stuff is not demonstrated here, including non-blocking keyboard input, nifty autodetection of terminal dimensions, other kinds of questions/answers, different layouts for menus, lists, and questions, and such things.