Limnoria/src/utils/iter.py
Jeremy Fincher 5fd6bbb52d Completely restructured our utils modules.
Tons of changes.  Here's the summary of things that matter most:

* There is no more supybot.fix.
* There is no more supybot.webutils; now there is supybot.utils.web.
  * It's no longer webutils.WebError, but just utils.web.Error.
* You shouldn't import itertools, ideally, but instead import utils.iter.
* No more using imap/ifilter in commands unless absolutely necessary.  It's
  premature optimization and annoying.
* utils.str.format isn't quite ready yet, but will be soon.  That'll be the
  next big thing to fix in our code.
2005-01-27 06:59:08 +00:00

148 lines
4.4 KiB
Python

###
# Copyright (c) 2002-2005, Jeremiah Fincher
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice,
# this list of conditions, and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions, and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
# * Neither the name of the author of this software nor the name of
# contributors to this software may be used to endorse or promote products
# derived from this software without specific prior written consent.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
###
import new
import random
from itertools import *
def len(iterable):
"""Returns the length of an iterator."""
i = 0
for _ in iterable:
i += 1
return i
def trueCycle(iterable):
while 1:
yielded = False
for x in iterable:
yield x
yielded = True
if not yielded:
raise StopIteration
def groupby(key, iterable):
if key is None:
key = lambda x: x
it = iter(iterable)
value = it.next() # If there are no items, this takes an early exit
oldkey = key(value)
group = [value]
for value in it:
newkey = key(value)
if newkey != oldkey:
yield group
group = []
oldkey = newkey
group.append(value)
yield group
def partition(p, iterable):
"""Partitions an iterable based on a predicate p.
Returns a (yes,no) tuple"""
no = []
yes = []
for elt in iterable:
if p(elt):
yes.append(elt)
else:
no.append(elt)
return (yes, no)
def any(p, iterable):
"""Returns true if any element in iterable satisfies predicate p."""
for elt in ifilter(p, iterable):
return True
else:
return False
def all(p, iterable):
"""Returns true if all elements in iterable satisfy predicate p."""
for elt in ifilterfalse(p, iterable):
return False
else:
return True
def choice(iterable):
if isinstance(iterable, (list, tuple)):
return random.choice(iterable)
else:
n = 1
m = new.module('') # Guaranteed unique value.
ret = m
for x in iterable:
if random.random() < 1/n:
ret = x
n += 1
if ret is m:
raise IndexError
return ret
def flatten(iterable, strings=False):
"""Flattens a list of lists into a single list. See the test for examples.
"""
for elt in iterable:
if not strings and isinstance(elt, basestring):
yield elt
else:
try:
for x in flatten(elt):
yield x
except TypeError:
yield elt
def split(isSeparator, iterable, maxsplit=-1, yieldEmpty=False):
"""split(isSeparator, iterable, maxsplit=-1, yieldEmpty=False)
Splits an iterator based on a predicate isSeparator."""
if isinstance(isSeparator, basestring):
f = lambda s: s == isSeparator
else:
f = isSeparator
acc = []
for element in iterable:
if maxsplit == 0 or not f(element):
acc.append(element)
else:
maxsplit -= 1
if acc or yieldEmpty:
yield acc
acc = []
if acc or yieldEmpty:
yield acc
def ilen(iterable):
i = 0
for _ in iterable:
i += 1
return i
# vim:set shiftwidth=4 tabstop=8 expandtab textwidth=78: