我有数据帧（df）由47列和30,000行组成，列在下面
Index(['Unnamed: 0', 'CtpJobId', 'TransformJobStateId', 'LastError',
'PriorityDate', 'QueuedTime', 'AccurateAsOf', 'SentToDevice',
'StartedAtDevice', 'ProcessStart', 'LastProgressAt', 'ProcessEnd',
'OutputFileDuration', 'Tags', 'SegmentId', 'VideoId',
'ClipFirstFrameNumber', 'ClipLastFrameNumber', 'SourceId',
'SourceNamedLocation', 'SourceDirectory', 'SourceFileSize',
'srcMediaFormat', 'srcFrameRate', 'srcWidth', 'srcHeight', 'srcCodec',
'srcDuration', 'TargetId', 'TargetNamedLocation', 'TargetDirectory',
'TargetFilename', 'Description', 'TargetTags', 'tgtFrameRate',
'tgtDropFrame', 'tgtWidth', 'tgtHeight', 'tgtCodec', 'DeviceType',
'DeviceResourceId', 'AssignedDeviceId', 'DeviceName',
'AssignedDeviceJobId', 'DeviceUri'],
dtype='object')
我想为选择列或数据帧应用一个函数来创建一个名为df['seg_duration']的新列，所以我的函数如下
def seq_duration(df):
if ClipFirstFrameNumber is not None and ClipLastFrameNumber is not None:
fn = ClipLastFrameNumber -ClipFirstFrameNumber
if FrameRate =='23.98' and DropFrame == 'False' :
fps = 24 / 1.001
elif FrameRate == '24' and DropFrame == 'False':
fps = 24
elif FrameRate == '25'and DropFrame == 'False':
fps = 25
elif FrameRate == '29.97':
fps = 30 / 1.001
elif FrameRate == '30' and DropFrame == 'False':
fps = 30
elif FrameRate == '59.94':
fps = 60 / 1.001
Duration = fn/fps
elif srcDuration is not None:
Duration = srcDuration
else:
None
该函数实际上有3种情况，在一种情况下有许多条件，所以首先我从ClipLastFrameNumber减去ClipFirstFrameNumber列的值，并将其保存为fn变量。
ClipLastFrameNumber ClipFirstFrameNumber tgtDropFrame tgtFrameRate
NaN NaN True 29.97
NaN NaN True 29.97
NaN NaN True 29.97
34354.0 28892.0 True 29.97
当我应用此函数时，如下所示
df['seg_duration']=df.apply(seq_duration)
我收到错误NameError:（“未定义名称'ClipFirstFrameNumber'，'发生在未命名的索引：0'）
这是为pandas编写函数的正确方法，还是我如何将此函数用于该数据帧并实现基于该函数创建新列df['seg_dur']的目标。提前谢谢
稍微修改一下您的函数：
def seq_duration(row):
Duration = None
if row.ClipFirstFrameNumber is not None and row.ClipLastFrameNumber is not None:
fn = row.ClipLastFrameNumber -row.ClipFirstFrameNumber
fps = 0
if row.FrameRate =='23.98' and row.DropFrame == 'False' :
fps = 24 / 1.001
elif row.FrameRate == '24' and row.DropFrame == 'False':
fps = 24
elif row.FrameRate == '25'and row.DropFrame == 'False':
fps = 25
elif row.FrameRate == '29.97':
fps = 30 / 1.001
elif row.FrameRate == '30' and row.DropFrame == 'False':
fps = 30
elif row.FrameRate == '59.94':
fps = 60 / 1.001
if fps>0:
Duration = fn/fps
elif row.srcDuration is not None:
Duration = row.srcDuration
return Duration
然后你要：
df['seg_duration']=df.apply(seq_duration,axis = 1)
