Default/editable string to raw_input

[Paraic Gallagher]

Hi,

This is my first post to the list, I hope somebody can help me with this
problem. Apologies if it has been posted before but I have been internet
searching to no avail.

What I am trying to do is provide a simple method for a user to change a
config file, for a test suite.
The config file consists of a number of keys, eg. build number, target
device, etc.

What I would like to do is give the user a key, and the previous value
for that key.
The user can then accept the previous value or edit it on the line.

I have a method where the previous value of a key is presented to the
user and can be accepted if the user hits return. But as some of the
values are somewhat long, and the user may only need to change 1 or 2
characters, it would be a nice feature to offer line editing.

I can get the readline.set_pr e_input_hook() function to send text after
a raw_input prompt, but this text cannot be edited.

Thanks in advance for any help.
Paraic.

[Sybren Stuvel]

Re: Default/editable string to raw_input

Paraic Gallagher enlightened us with:[color=blue]
> What I am trying to do is provide a simple method for a user to
> change a config file, for a test suite.[/color]

My opinion: let the user edit the configuration file using his/her
favourite text editor. Someone configuring a test suite should
certainly be able to edit a text file.

Sybren
--
The problem with the world is stupidity. Not saying there should be a
capital punishment for stupidity, but why don't we just take the
safety labels off of everything and let the problem solve itself?
Frank Zappa

[Paraic Gallagher]

Re: Default/editable string to raw_input

Sybren Stuvel wrote:
[color=blue]
>My opinion: let the user edit the configuration file using his/her
>favourite text editor. Someone configuring a test suite should
>certainly be able to edit a text file.
>
>Sybren
>
>[/color]
While I agree in principal to your opinion, the idea is that an absolute
moron
would be able to configure a testcell with smallest amount of effort
possible.

Moreover, I am curious as to whether somebody else out there knows if
there is a solution to the problem.

Paraic.

[Sybren Stuvel]

Re: Default/editable string to raw_input

Paraic Gallagher enlightened us with:[color=blue]
> While I agree in principal to your opinion, the idea is that an
> absolute moron would be able to configure a testcell with smallest
> amount of effort possible.[/color]

Then explain to me why learning how to use your program to edit the
file is easier than using an already familiar program.
[color=blue]
> Moreover, I am curious as to whether somebody else out there knows
> if there is a solution to the problem.[/color]

Give a default answer that's chosen when the user presses enter
without providing an answer of his own.

Sybren
--
The problem with the world is stupidity. Not saying there should be a
capital punishment for stupidity, but why don't we just take the
safety labels off of everything and let the problem solve itself?
Frank Zappa

[David Wahler]

Re: Default/editable string to raw_input


Paraic Gallagher wrote:[color=blue]
> Hi,
>
> This is my first post to the list, I hope somebody can help me with this
> problem. Apologies if it has been posted before but I have been internet
> searching to no avail.
>
> What I am trying to do is provide a simple method for a user to change a
> config file, for a test suite.
> The config file consists of a number of keys, eg. build number, target
> device, etc.
>
> What I would like to do is give the user a key, and the previous value
> for that key.
> The user can then accept the previous value or edit it on the line.
>
> I have a method where the previous value of a key is presented to the
> user and can be accepted if the user hits return. But as some of the
> values are somewhat long, and the user may only need to change 1 or 2
> characters, it would be a nice feature to offer line editing.
>
> I can get the readline.set_pr e_input_hook() function to send text after
> a raw_input prompt, but this text cannot be edited.[/color]

With the disclaimer that, as others have said, this may not be the best
user-interface choice:

import readline
readline.set_st artup_hook(lamb da: readline.insert _text(old_value ))
try:
new_value = raw_input()
finally:
readline.set_st artup_hook(None )

Note that, among other issues, this isn't threadsafe (but then, you
really shouldn't be doing console I/O from multiple threads anyway).
Hope this helps.

-- David

[Paraic Gallagher]

Re: Default/editable string to raw_input

David Wahler wrote:
[color=blue]
>With the disclaimer that, as others have said, this may not be the best
>user-interface choice:
>
> import readline
> readline.set_st artup_hook(lamb da: readline.insert _text(old_value ))
> try:
> new_value = raw_input()
> finally:
> readline.set_st artup_hook(None )
>
>Note that, among other issues, this isn't threadsafe (but then, you
>really shouldn't be doing console I/O from multiple threads anyway).
>Hope this helps.
>
>-- David
>
>
>[/color]
Thanks David, this was exactly what I was looking for.

Paraic.

[Sion Arrowsmith]

Re: Default/editable string to raw_input

Sybren Stuvel <sybrenUSE@YOUR thirdtower.com. imagination> wrote:[color=blue]
>Paraic Gallagher enlightened us with:[color=green]
>> While I agree in principal to your opinion, the idea is that an
>> absolute moron would be able to configure a testcell with smallest
>> amount of effort possible.[/color]
>Then explain to me why learning how to use your program to edit the
>file is easier than using an already familiar program.[/color]

You're assuming that the tester is already familiar with a text
editor. And then they would have to learn the syntax of the
configuration file, and the parameters available. A point-and-
drool interface requires no such learning.

--
\S -- siona@chiark.gr eenend.org.uk -- http://www.chaos.org.uk/~sion/
___ | "Frankly I have no feelings towards penguins one way or the other"
\X/ | -- Arthur C. Clarke
her nu becomeþ se bera eadward ofdun hlæddre heafdes bæce bump bump bump

[Sybren Stuvel]

Re: Default/editable string to raw_input

Sion Arrowsmith enlightened us with:[color=blue]
> You're assuming that the tester is already familiar with a text
> editor.[/color]

Indeed. Someone working on a test suite sounded like someone who knows
how to work with a text editor.
[color=blue]
> And then they would have to learn the syntax of the configuration
> file, and the parameters available.[/color]

True. Thorough comments and a clear syntax help a long way.
[color=blue]
> A point-and-drool interface requires no such learning.[/color]

But that's not what you get with raw_input().

Sybren
--
The problem with the world is stupidity. Not saying there should be a
capital punishment for stupidity, but why don't we just take the
safety labels off of everything and let the problem solve itself?
Frank Zappa

[Ognjen Bezanov]

Converting hex to char help

Hi all, I am trying to convert a hexdecimal value to a char using this code:

print ' %c ' % int(0x62)

this works fine, but if I want to do this:

number = "62"
print ' %c ' % int("0x" + number)

I get an error:

Traceback (most recent call last):
File "<stdin>",l ine 1, in ?
ValueError: invalid literal for in(): 0x62

How can I convert a string "0x62" to int/hex without this problem?

Thanks!

[Sybren Stuvel]

Re: Converting hex to char help

Ognjen Bezanov enlightened us with:[color=blue]
> Hi all, I am trying to convert a hexdecimal value to a char using this code:
>
> print ' %c ' % int(0x62)[/color]
This is an integer ^^^^

[color=blue]
> this works fine, but if I want to do this:
>
> number = "62"
> print ' %c ' % int("0x" + number)[/color]
This is a string ^^^^^^^^^^^^^
[color=blue]
> How can I convert a string "0x62" to int/hex without this problem?[/color]

In [0]: exec('num=0x%s' % '62')

In [1]: num
Out[1]: 98


Sybren
--
The problem with the world is stupidity. Not saying there should be a
capital punishment for stupidity, but why don't we just take the
safety labels off of everything and let the problem solve itself?
Frank Zappa

[Tim Chase]

Re: Converting hex to char help

> How can I convert a string "0x62" to int/hex without this problem?

The call to int() takes an optional parameter for the base:
[color=blue][color=green][color=darkred]
>>> print int.__doc__[/color][/color][/color]
int(x[, base]) -> integer

Convert a string or number to an integer, if possible. A
floating point argument will be truncated towards zero (this
does not include a string representation of a floating point
number!) When converting a string, use the optional base.
It is an error to supply a base when converting a
non-string. If the argument is outside the integer range a
long object will be returned instead.
[color=blue][color=green][color=darkred]
>>> int('0x62', 16)[/color][/color][/color]
98

-tkc

[Ognjen Bezanov]

Re: Converting String to int

Hi all, Another problem, with the same error (error: "invalid literal for
int()")

code:

mynums = "423.523.674.32 4.342.122.943.4 21.762.158.830"

mynumArray = string.split(my nums,".")

x = 0
for nums in mynumArray:
if nums.isalnum() == true:
x = x + int(nums)
else:
print "Error, element contains some non-numeric characters"
break


/end code

This seemed like a simple thing, and I have done it before with no issues.
have I missed something obvious? taking into account my previous hex
question, I tried changing int(nums) to int(nums,10) but it still gives me
the error

[Heiko Wundram]

Re: Converting String to int

Am Sonntag 14 Mai 2006 22:23 schrieb Ognjen Bezanov:[color=blue]
> mynums = "423.523.674.32 4.342.122.943.4 21.762.158.830"
>
> mynumArray = string.split(my nums,".")[/color]

This is the old way of using string functions using the module string. You
should only write this as:

mynumArray = mynums.split(". ")

(using the string methods of string objects directly)
[color=blue]
> x = 0
> for nums in mynumArray:[/color]

This is misleading. Rename the variable to num, as it only contains a single
number.
[color=blue]
> if nums.isalnum() == true:[/color]

..isalnum() checks whether the string consists of _alpha_-numeric characters
only. So, in this case, it may contain letters, among digits. .isdigit()
checks whether it is a (base <= 10) number.
[color=blue]
> x = x + int(nums)
> else:
> print "Error, element contains some non-numeric characters"[/color]

As you don't know what the offending element is, insert a:

print nums

here.
[color=blue]
> break[/color]

If you change the code as noted above, it works fine for me.

--- Heiko.

[Tim Chase]

Re: Converting String to int

> Hi all, Another problem, with the same error (error: "invalid literal for[color=blue]
> int()")[/color]

Having the actual code would be helpful...
[color=blue]
> code:
>
> mynums = "423.523.674.32 4.342.122.943.4 21.762.158.830"
>
> mynumArray = string.split(my nums,".")
>
> x = 0
> for nums in mynumArray:
> if nums.isalnum() == true:[/color]

This line would likely bomb, as in python, it's "True", not
"true" (unless you've defined lowercase versions elsewhere)
[color=blue]
> x = x + int(nums)
> else:
> print "Error, element contains some non-numeric characters"
> break[/color]

However, I modified your code just a spot, and it worked
like a charm:

mynums = "423.523.674.32 4.342.122.943.4 21.762.158.830"
mynumArray = mynums.split(". ")
x = 0
for num in mynumArray:
if num.isdigit():
x = x + int(num)
else:
print "Error"
break

and it worked fine.

A more pythonic way may might be

x = sum([int(q) for q in mynumArray if q.isdigit()])

or, if you don't need mynumArray for anything, you can just use

x = sum([int(q) for q in mynum.split("." ) if q.isdigit()])

Hope this gives you some stuff to work with,

-tkc