is_sorted.py

from iteration_utilities import all_monotone

from itertools import tee
import operator

def is_sorted_by_alexandre(iterable, compare=operator.le):
    a, b = tee(iterable)
    next(b, None)
    return all(map(compare, a, b))

def is_sorted_using_sorted(iterable):
    return sorted(iterable) == iterable

def is_sorted_by_timgeb(lst):
    return all(x <= y for x,y in zip(lst, lst[1:]))

def is_sorted_by_sergey(l):
    l2 = iter(l)
    next(l2, None)
    return all(a <= b for a, b in zip(l, l2))

def is_sorted_by_wai(l):
    all(l[i] <= l[i+1] for i in range(len(l)-1))
    
def is_sorted_by_paul(l):
    return all(a <= b for a, b in zip(l[:-1], l[1:]))

def is_sorted_by_aaronasterling(lst, key=lambda x, y: x < y):
    for i, el in enumerate(lst[1:], 1):
        if key(el, lst[i-1]):
            return False
    return True

def is_sorted_by_AmitMoscovich(lst):
    it = iter(lst)
    try:
        prev = next(it)
    except StopIteration:
        return True
    for x in it:
        if prev > x:
            return False
        prev = x
    return True

# sorted list
l = list(range(10000))

%timeit all_monotone(l)
%timeit is_sorted_using_sorted(l)
%timeit is_sorted_by_AmitMoscovich(l)
%timeit is_sorted_by_alexandre(l)
%timeit is_sorted_by_timgeb(l)
%timeit is_sorted_by_paul(l)
%timeit is_sorted_by_sergey(l)
%timeit is_sorted_by_wai(l)
%timeit is_sorted_by_aaronasterling(l)

# unsorted list
l = [10] + list(range(10000))

%timeit all_monotone(l)
%timeit is_sorted_using_sorted(l)
%timeit is_sorted_by_AmitMoscovich(l)
%timeit is_sorted_by_alexandre(l)
%timeit is_sorted_by_timgeb(l)
%timeit is_sorted_by_paul(l)
%timeit is_sorted_by_sergey(l)
%timeit is_sorted_by_wai(l)
%timeit is_sorted_by_aaronasterling(l)