Gilles Ganault wrote:
On Fri, 22 Jan 2010 09:49:32 -0500, Dave Angel <da...@ieee.org> wrote:
Seems to me the other solutions I've seen so far are more complex than
needed. I figure you either want an unordered list, in which case you
could use random.shuffle(), or you want a list that's sorted, but starts
somewhere in the middle, at an arbitrary place, goes to the end, and
wraps back to the beginning. So use random.randint() to choose an index
within the list, and concatenate two slices of the list, based on that
index in reverse order.
Yes, this is exactly what I need: Start listing items from a given
index (actually, using a character since the list contains names) all
the way to the end of the list; If the character wasn't the very
first, go back to the first time and display the list until we get to
the current character.
Python is so feature-rich, I'm sure there's a much simpler way to do
this than this crappy code of mine:
=============
connected = []
connected.append("0dummy")
connected.append("aa")
connected.append("bb")
connected.append("cc")
index = 0
for item in connected:
#For testing purposes;
#Final code will read/increment character from file
if item[index] == "b":
break
else:
index = index + 1
#Print items between current character and end of list
tempindex = index
while(tempindex < len(connected)):
print connected[tempindex]
tempindex = tempindex + 1
#if current letter not first character,
#display beginning of list up to current character
if index != 0:
tempindex = 0
while tempindex < index:
print connected[tempindex]
tempindex = tempindex + 1
=============
Thank you for any help
Your code would fail if you picked a letter for which there were no
entries. That's easily fixed, just use >= instead of == in your if test.
Jean-Michel Pichavant post implements my second option. So I'll borrow
his code here.
But apparently you want my third option: random starting place, but
with all the names starting with the same character together. To get
that, but with the distribution proportional to the number of names that
start with the given character, you need to get the index in two
stages. First use the random.randint(). Then do a search for the first
name that starts with that same character. For that, I borrow from
Duncan Booth, and use bisect.bisect().
import random, bisect
connected = sorted( ['jj', '0test', '3test', 'aa', 'aj', 'bb', 'bz',
'dc', 'df'] )
def getNewOrder(myList):
index = random.randint(0,len(myList)-1)
startch = myList[index][0]
pos = bisect.bisect_left(myList, startch)
print index, myList[index], pos, myList[pos]
return myList[pos:] + myList[:pos] # using slicing instead of list
comprehension (suggested by DaveA)
print connected
for i in range(6):
print getNewOrder(connected)
I have the extra print inside the function to show (for example) that if
'aj' is picked, it actually will start with'aa'
Note that with your constraints, there's no way it can be fair. But
experiment a bit, and see if it meets your needs.
DaveA
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