Re: How to implement function like this?

[Loic Mahe]

even shorter:

def funcA(tarray):
 s = min(len(tarray), 3)
 return [2, 3, 4][0:s] + [e for e in funcB(3-s)[0:3-s]]
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Re: How to implement function like this?

[Loic Mahe]

Marc 'BlackJack' Rintsch a écrit :
> On Tue, 23 Oct 2007 11:48:08 +0200, Loic Mahe wrote:
> 
>> even shorter:
>>
>> def funcA(tarray):
>>  s = min(len(tarray), 3)
>>  return [2, 3, 4][0:s] + [e for e in funcB(3-s)[0:3-s]]
> 
> Why the list comprehension!?
> 
> Ciao,
>   Marc 'Blackjack' Rintsch

sorry I just read too fast
and thought he worked with lists ...
anyway 'e for e in' and so list comprehension was useless here

def funcA(tarray):
  s = min(len(tarray), 3)
  return (2, 3, 4,)[0:s] + funcB(3-s)[0:3-s]

this is ok if funcB(...) returns a tuple ...
if it returns a list just add: tuple(funcB(...))

note: list comprehension transforms a tuple into a list
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Re: Some "pythonic" suggestions for Python

[Loic Mahe]

Frank Samuelson a écrit :
> foo = function(x,y) x+y*2   # Example S language code
> bar = foo
> bar(3,4)
> m = lapply( s, foo )
> bb = lapply(s, function(t) t[3]*4 )

Here you want all functions to be lambda functions:

you can get something very close to what you want,
just like this:

foo = lambda x,y: x+y*2
bar = foo
bar(3,4)

you would only need to extend existing lambda:
  * support all python keywords/expressions in lambda
  * multiline lambda
  * multi return value lambda
  * and possibility to map 'function' name to be equivalent to 'lambda'


Loic
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Re: Some "pythonic" suggestions for Python

[Loic Mahe]

Chris M write :
> Multi-return value lambda? Just so you know, there is no concept of
> returning more than one value from a function.

I wrote:
 > * multi return value lambda

I meant: multiple return statement, not return multiple values

pseudo code here:

lambda x: if A return B, if C return D, if E return F ...

it could be nice if ou could write normal functions ... as lambda ones
and not being limited to a subset of the kewords ...

at least it would fit Frank Samuleson needs/wishes better...
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Re: Equivalent of TCL's "subst" ?

[Loic Mahe]

gamename a écrit :
> Hi,
> 
> In TCL, you can do things like:
> set foobar "HI!"
> set x foo
> set y bar
> subst $$x$y
> HI!
> 
> Is there a way to do this type of evaluation in python?
> 
> TIA,
> -T
> 

you can also try using eval:

 >>> foobar = "HI!"
 >>> x = 'foo'
 >>> y = 'bar'
 >>> print eval(x+y)
HI!



Loic
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Re: Convert some Python code to C++

[Loic Mahe]

[EMAIL PROTECTED] a écrit :
> For those that understand algorithms and can talk Python, I want to
> convert the Python code in the section "Reading out all LCSs" into C++
> code but I don't understand some of the syntax.  Can anyone give me a
> hand?
> 
> def backTrackAll(C, X, Y, i, j):
> if i == 0 or j == 0:
> return set([""])
> elif X[i-1] == Y[j-1]:
> return set([Z + X[i-1] for Z in backTrackAll(C, X, Y, i-1,
> j-1)])
> else:
> R = set()
> if C[i][j-1] >= C[i-1][j]:
> R.update(backTrackAll(C, X, Y, i, j-1))
> if C[i-1][j] >= C[i][j-1]:
> R.update(backTrackAll(C, X, Y, i-1, j))
> return R
> 
> Thanks!
> 

just have a look at this tutorial: and look for Lists and Sets
http://docs.python.org/tut/tut.html

and look in the reference index for set() and list() in
http://docs.python.org/lib/genindex.html


or just pick the algo in another language in the url you give

or tell us precisely what part of the python algo you do not understant!
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