Question

我使用嵌套的while循环解决了以下问题。有没有办法以简单的Pythonic方式解决问题？

问题：

定义一个过程，该过程接收来自1 - 9的一串数字，并输出包含以下参数的列表：


字符串中的每个数字都应插入列表中。

如果字符串中的数字x小于或等于前面的数字y，则应将数字x插入子列表中。

继续将以下数字添加到子列表中，直到达到大于z的数字y。

然后将此号码z添加到正常列表中并继续。


他们将后续数据与前一数字进行比较。

例如：
string = '543987'
result = [5,[4,3],9,[8,7]]

string= '987654321'
result = [9,[8,7,6,5,4,3,2,1]]

string = '455532123266'
result = [4, 5, [5, 5, 3, 2, 1, 2, 3, 2], 6, [6]]

我的代码：

def numbers_in_lists(string):
    array = []
    for i in string:
        array.append(int(i))
    temp_list = []
    final_list = [array[0]]    
    i = 0
    while i+1 < len(array):
        if array[i] >= array[i+1]:
            j = 0
            while j+1 < len(array[i:]) and array[i] >= array[i:][j+1]:
                temp_list.append(array[i:][j+1])
                j += 1
            final_list.append(temp_list)
            i += len(temp_list)
            temp_list = []            
        else:
            final_list.append(array[i+1])
            i += 1            
    #print final_list
    return final_list

string = '543987'

print numbers_in_lists(string)
[5, [4, 3], 9, [8, 7]]

Answer 1

你当然可以简化方法;我会这样做：

def numbers_in_lists(string):
    """Describe what it does here!""" 
    output = []
    sublist = []
    for num in map(int, string):
        if not output or num > output[-1]:
            if sublist:
                output.append(sublist)
                sublist = []
            output.append(num)
        else:
            sublist.append(num)
    if sublist:
        output.append(sublist)
    return output

使用中：

>>> numbers_in_lists('543987')
[5, [4, 3], 9, [8, 7]]
>>> numbers_in_lists('987654321')
[9, [8, 7, 6, 5, 4, 3, 2, 1]]
>>> numbers_in_lists('455532123266')
[4, 5, [5, 5, 3, 2, 1, 2, 3, 2], 6, [6]]

Answer 2

好吧......加我2美分： - ）

def custom_func(input_string):
    if not input_string:
        return []

    value = input_string[0]
    output_list = [int(value)]

    for char in input_string[1:]:
        if char > value:
            # Encountered a value higher than the past maximum
            output_list.append(int(char))
        else:
            if value == str(output_list[-1]):
                # First value that is lesser than the past maximum
                output_list.append([int(char)])
            else:
                # nth value which is lesser than the past maximum
                output_list[-1].append(int(char))
        value = char # updating the past maximum

    return output_list

Answer 3

这是解决方案，您应该考虑。

num = '455532123266'
final_list = [];

prev = 0
sublist = []
for n in num:
    n = int(n)
    if (n > prev):
        if (sublist != []):
            final_list.append(sublist)
            sublist = []
        final_list.append(n)

    else:
        sublist.append(n)
    prev = n

if sublist != []:
    final_list.append(sublist)   

print final_list

[4, 5, [5, 5, 3, 2, 1], 2, 3, [2], 6, [6]]

Answer 4

问题定义不明确，因为示例输入并未完全阐明2个问题：

'567'会发生什么 - 如果每个号码后都有空列表
该示例无法判断您是将后续数字与前一个数字或递减子序列的第一个数字进行比较！

~~因此，这是我的看法，它不一定是最pythonic，但我无法想出更多的pythonic解决方案。~~

def numbers_in_lists(string): current_min = -1 # larger than any digit rv = [] current_list = [] def push_sublist(): if current_list: largest = current_list.pop(0) rv.extend([largest, current_list]) for digit in map(int, string): if digit > current_min: push_sublist() current_list = [] current_min = digit current_list.append(digit) push_sublist() # if remaining return rv

我怀疑，这个问题一点也不清楚。考虑到示例代码如何工作，我设计了一个新算法

def numbers_in_lists(string):
    current_min = -1  # larger than any digit
    rv = []
    current_list = []

    def push_sublist():
        if current_list:
            largest = current_list.pop(0)
            rv.append(largest)
            if current_list:
                rv.append(current_list)

    for digit in map(int, string):
        if digit > current_min:
            push_sublist()
            current_list = []
            current_min = digit

        current_list.append(digit)

    push_sublist()  # if remaining
    return rv

Answer 5

我的是懒惰的人：

def num_and_sublist_generator(iterable):
    start = -1
    sublist = []
    for n in iterable:
        if n > start:
            if sublist:
                yield sublist
                sublist = []
            start = n
            yield n
        else:
            sublist.append(n)
    if sublist:
        yield sublist

def numbers_in_lists(string):
    return list(num_and_sublist_generator(map(int, string)))

Answer 6

我会考虑以更实用的方式进行。

def solve(input):
    pairs = zip(input, input[1:])
    sublist = [False] + map(lambda x: x[0] > x[1], pairs)

    result = []
    for (val, to_sublist) in zip(input, sublist):
        if not to_sublist:
            result.append(val)
        else:
            if isinstance(result[-1], list):
                result[-1].append(val)
            else:
                result.append([val])
    return result

这允许分离检查to_sublist谓词和结果数据结构的实际构建。据我所知，第一个数字永远不会进入子列表，所以它始终以False开头。

Answer 7

我能想到的最简单的解决方案是在实际的问题陈述之后：

def numbers_in_lists(string):
    output = []
    sublist = []
    for number in [int(c) for c in string]: # Every number in the string should be inserted into the list.
        if output and number <= output[-1]:
            """
            - If a number x in the string is less than or equal
              to the preceding number y, the number x should be
              inserted into a sublist.
            - Continue adding the following numbers to the sublist
              until reaching a number z that is greater than the number y.
            """
            sublist.append(number)
        else:
            """
            - Then add this number z to the normal list and continue.
            """
            if sublist:
                output.append(sublist)
                sublist = []
            output.append(number)
    if sublist:
        output.append(sublist)
    return output

Answer 8

另一种做法......虽然可能会令人困惑

_val = int(string[0])
my_lis = [_val]
temp_li = []
for  i in string[1:]:
    _cval = int(i)
    if _cval > _val:
        if temp_li:
            my_lis.append(temp_li[:])
            temp_li = []
        my_lis.append(_cval)
        _val = _cval
    else:
        temp_li.append(_cval)
        _val =  temp_li[0]
if temp_li: my_lis.append(temp_li[:])# last value
print string
print my_lis

python中的列表概念列表

8 个答案: