Question

假设我有一个如下所示的列表。你怎么能遍历列表并替换之间的零之间的零点，其间的零长度可以变化？

输入：

mylist = [0,0,0,1,0,0,0,0,1,0,0,0,0,1,0,0,1,0,0]

输出：

mylist = [0,0,0,1,1,1,1,1,1,0,0,0,0,1,1,1,1,0,0]

Answer 1

我认为你可以分两个阶段做到这一点：

首先我们获得指示的指数;和
我们一次拿两个，然后用一个填充。

像：

import pandas as pd
data = pd.read_excel('D:Downloads/titanic3.xls')

data.head()
Out[7]: 
   pclass  survived                                             name     sex  \
0       1         1                    Allen, Miss. Elisabeth Walton  female   
1       1         1                   Allison, Master. Hudson Trevor    male   
2       1         0                     Allison, Miss. Helen Loraine  female   
3       1         0             Allison, Mr. Hudson Joshua Creighton    male   
4       1         0  Allison, Mrs. Hudson J C (Bessie Waldo Daniels)  female   

       age  sibsp  parch  ticket      fare    cabin embarked boat   body  \
0  29.0000      0      0   24160  211.3375       B5        S    2    NaN   
1   0.9167      1      2  113781  151.5500  C22 C26        S   11    NaN   
2   2.0000      1      2  113781  151.5500  C22 C26        S  NaN    NaN   
3  30.0000      1      2  113781  151.5500  C22 C26        S  NaN  135.0   
4  25.0000      1      2  113781  151.5500  C22 C26        S  NaN    NaN   

                         home.dest  
0                     St Louis, MO  
1  Montreal, PQ / Chesterville, ON  
2  Montreal, PQ / Chesterville, ON  
3  Montreal, PQ / Chesterville, ON  
4  Montreal, PQ / Chesterville, ON

这会产生：

# obtain an iterable of the indices of the ones
ones = iter([i for i,x in enumerate(mylist) if x == 1])

# for every pair of indices
for i0,i1 in zip(ones,ones):
    # iterate over the range
    for j in range(i0+1,i1):
        # and assign 1 to these indices
        mylist[j] = 1

Answer 2

保持旗帜，无论你在哪里＆＃34;内部＆＃34; 1-1块（你需要更新0到1）或不。

这假设，单个（＆＃34; last＆＃34;）1将生成一个直到列表末尾：

inside = False
for x in range(len(data)):
  if data[x]:
    inside = not inside
  elif inside:
    data[x] = 1
[ 0, 1, 0, 1, 0 ] -> [ 0, 1, 1, 1, 0 ]
[ 0, 1, 0, 0, 0 ] -> [ 0, 1, 1, 1, 1 ]

如果不是你想要的，那么最后1应该被忽略：

start_block = None
for x in range(len(data)):
  if data[x]:
    if start_block is not None:
      for y in range(start_block + 1, x):
        data[y] = 1
      start_block
    else: 
      start_block = x
[ 0, 1, 0, 1, 0 ] -> [ 0, 1, 1, 1, 0 ]
[ 0, 1, 0, 0, 0 ] -> [ 0, 1, 0, 0, 0 ]

将列表中的0之间的零替换为零

2 个答案: