正在研究熊猫，需要根据列中的值删除DataFrame中的n个连续行。
在下面的示例中，在17:00:01有一个事件持续2秒钟。在这段时间内，我需要以下2行。在17:00:04还有另一个事件，然后应删除17:00:05行。
不确定如何处理此问题。在lamda中使用遮罩？
Traceback (most recent call last):
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/core/handlers/exception.py", line 34, in inner
response = get_response(request)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/core/handlers/base.py", line 115, in _get_response
response = self.process_exception_by_middleware(e, request)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/core/handlers/base.py", line 113, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/views/decorators/csrf.py", line 54, in wrapped_view
return view_func(*args, **kwargs)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/views/generic/base.py", line 71, in view
return self.dispatch(request, *args, **kwargs)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/rest_framework/views.py", line 497, in dispatch
response = self.handle_exception(exc)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/rest_framework/views.py", line 457, in handle_exception
self.raise_uncaught_exception(exc)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/rest_framework/views.py", line 468, in raise_uncaught_exception
raise exc
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/rest_framework/views.py", line 494, in dispatch
response = handler(request, *args, **kwargs)
File "/home/shawn-codoid/Music/srfi-api/User/views.py", line 69, in post
form_data.save() # File Save
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/rest_framework/serializers.py", line 213, in save
self.instance = self.create(validated_data)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/rest_framework/serializers.py", line 932, in create
instance = ModelClass._default_manager.create(**validated_data)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/db/models/manager.py", line 82, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/db/models/query.py", line 422, in create
obj.save(force_insert=True, using=self.db)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/db/models/base.py", line 741, in save
force_update=force_update, update_fields=update_fields)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/db/models/base.py", line 779, in save_base
force_update, using, update_fields,
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/db/models/base.py", line 870, in _save_table
result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/db/models/base.py", line 908, in _do_insert
using=using, raw=raw)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/db/models/manager.py", line 82, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/db/models/query.py", line 1186, in _insert
return query.get_compiler(using=using).execute_sql(return_id)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/db/models/sql/compiler.py", line 1334, in execute_sql
for sql, params in self.as_sql():
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/db/models/sql/compiler.py", line 1278, in as_sql
for obj in self.query.objs
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/db/models/sql/compiler.py", line 1278, in <listcomp>
for obj in self.query.objs
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/db/models/sql/compiler.py", line 1277, in <listcomp>
[self.prepare_value(field, self.pre_save_val(field, obj)) for field in fields]
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/db/models/sql/compiler.py", line 1218, in prepare_value
value = field.get_db_prep_save(value, connection=self.connection)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/db/models/fields/__init__.py", line 789, in get_db_prep_save
return self.get_db_prep_value(value, connection=connection, prepared=False)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/db/models/fields/__init__.py", line 1273, in get_db_prep_value
value = self.get_prep_value(value)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/db/models/fields/__init__.py", line 1268, in get_prep_value
return self.to_python(value)
File "/home/shawn-codoid/Music/virtual/lib/python3.6/site-packages/django/db/models/fields/__init__.py", line 1243, in to_python
params={'value': value},
django.core.exceptions.ValidationError: ["'' value has an invalid date format. It must be in YYYY-MM-DD format."]
[03/Oct/2019 12:29:15] "POST /api/register/ HTTP/1.1" 500 214929
我有：
t = pd.to_timedelta(df['EventSeconds'], unit='s')
mask = df['2019-01-07 17:00:02' : '2019-01-07 17:00:02' + t]
我需要：
Index EventSeconds OtherColumn
07/01/2019 16:59:59 0 2
07/01/2019 17:00:00 2 3
07/01/2019 17:00:01 0 4
07/01/2019 17:00:02 0 5
07/01/2019 17:00:03 0 6
07/01/2019 17:00:04 1 7
07/01/2019 17:00:05 0 8
07/01/2019 17:00:06 0 9
答案 0 :(得分：1)
您可以将持续时间添加到Index中以获得结束时间，但是即使ffill秒，您也需要使用0：
t = pd.to_timedelta(df['EventSeconds'], unit='s')
# print end_times to see details
end_times = (df['Index'].add(t) # calculate the end time
.where(df['EventSeconds'].ne(0)) # mask the starting events
.ffill() # fill the same end times
)
df[df['Index'].gt(end_times)| df['EventSeconds'].ne(0) ]
输出：
Index EventSeconds
0 2019-07-01 16:59:59 0
1 2019-07-01 17:00:00 2
4 2019-07-01 17:00:03 0
5 2019-07-01 17:00:04 1
7 2019-07-01 17:00:06 0