关于使用reduce()和lambda。这里有一个工作代码，我个人认为比其他一些答案更好。

reduce(lambda x, y: (x[1]==y, y), [2, 2, 2], (True, 2))

返回一个元组，其中第一个值是布尔值，如果所有项都相同或不相同。

我怀疑这是“最python化的”，但类似于:

>>> falseList = [1,2,3,4]
>>> trueList = [1, 1, 1]
>>> 
>>> def testList(list):
...   for item in list[1:]:
...     if item != list[0]:
...       return False
...   return True
... 
>>> testList(falseList)
False
>>> testList(trueList)
True

会成功的。

出现使用itertools。Groupby(参见itertools食谱):

from itertools import groupby

def all_equal(iterable):
    g = groupby(iterable)
    return next(g, True) and not next(g, False)

或不带groupby:

def all_equal(iterator):
    iterator = iter(iterator)
    try:
        first = next(iterator)
    except StopIteration:
        return True
    return all(first == x for x in iterator)

您可以考虑使用许多其他的一行程序:

Converting the input to a set and checking that it only has one or zero (in case the input is empty) items def all_equal2(iterator): return len(set(iterator)) <= 1 Comparing against the input list without the first item def all_equal3(lst): return lst[:-1] == lst[1:] Counting how many times the first item appears in the list def all_equal_ivo(lst): return not lst or lst.count(lst[0]) == len(lst) Comparing against a list of the first element repeated def all_equal_6502(lst): return not lst or [lst[0]]*len(lst) == lst

但它们也有一些缺点，即:

all_equal and all_equal2 can use any iterators, but the others must take a sequence input, typically concrete containers like a list or tuple. all_equal and all_equal3 stop as soon as a difference is found (what is called "short circuit"), whereas all the alternatives require iterating over the entire list, even if you can tell that the answer is False just by looking at the first two elements. In all_equal2 the content must be hashable. A list of lists will raise a TypeError for example. all_equal2 (in the worst case) and all_equal_6502 create a copy of the list, meaning you need to use double the memory.

在Python 3.9中，使用perfplot，我们得到这些计时(越低的Runtime [s]越好):

或者使用numpy的diff方法:

import numpy as np
def allthesame(l):
    return np.all(np.diff(l)==0)

并呼吁:

print(allthesame([1,1,1]))

输出:

True

您可以将列表转换为集合。集合不能有重复项。所以如果原始列表中的所有元素都是相同的，那么集合就只有一个元素。

if len(set(input_list)) == 1:
    # input_list has all identical elements.

简单的解决方案是应用set on list

如果所有元素都相同，len将为1，否则大于1

lst = [1,1,1,1,1,1,1,1,1]
len_lst = len(list(set(lst)))

print(len_lst)

1


lst = [1,2,1,1,1,1,1,1,1]
len_lst = len(list(set(lst)))
print(len_lst)

2