我有一个pandas列,列出了用户所做的连续日志操作,同时在每个整个日志记录会话中在移动应用程序中发布照片.假设单个列表如下所示：
my_list = [
'action_a','action_b','action_c','action_z','action_j','action_a','action_z']
1)action_a – 照片上传的开始
2)action_z – 照片上传结束
3)其他actions_i – action_a和action_z之间可能发生的所有操作.
4)可能存在错误,例如’action_j’,它们不在’action_a’,’action_z’之间,我们不应该将它们考虑在内
5)照片上传过程可能无法完成 – 因此可能存在’action_a’,’action_b’之类的路径.
GOAL =将my_list分隔为以’action_a’开头并以’action_z’结尾或在另一’action_a’之前结束的所有操作路径的子列表.所以结果应该是这样的：
['action_a','action_z'] ['action_a','action_b'] ['action_a','action_z']
所以目前我正试图解决这个问题：首先我删除了所有的my_lists,其中’action_z’的数量大于’action_a’的数量或者没有’action_a’的数量.然后我做到了：
indices_a = [i for i,x in enumerate(my_list) if x == "action_a"]
indices_z = [i for i,x in enumerate(my_list) if x == "action_z"]
if(len(indices_z)<1):
for i_a,x_a in enumerate(indices_a):
if (i_a+1 != len(indices_a)):
indices_z.append(indices_a[i_a+1]-1)
else: indices_z.append(len(my_list)-1)
else:
for i_a,x_a in enumerate(indices_a):
if (i_a+1 != len(indices_a)):
if (indices_z[i_a] > indices_a[i_a+1] ):
indices_z.insert(i_a,indices_a[i_a+1]-1)
else: indices_z.append(len(my_list)-1)
res=[]
for i,j in zip(indices_a,indices_z):
res.append(my_list[i:j+1] )
好像它有效.有什么更好的方法？
解决方法
我试图简化一些事情并提出这个逻辑：
result = []
curr_list = None
for item in my_list:
if item == 'action_a':
if curr_list is not None:
# Only append is there is content
result.append(curr_list)
# Create a new list
curr_list = []
try:
# Try to append the current item
curr_list.append(item)
if item == 'action_z':
# Close the current list but don't initialize
# a new one until we encounter action_a
result.append(curr_list)
curr_list = None
except AttributeError:
# This means we haven't encountered action_a yet
# Just ignore and move on
pass
if curr_list is not None:
# Append an "open" list if there is one
result.append(curr_list)
for item in result:
print(item)
结果：
['action_a','action_z'] ['action_a','action_z']