Python 添加一列,该列为满足另一列上条件的每个索引递增
我试图从数据帧生成一列,以作为分组的基础。我知道非NaN列下的每个NaN列都属于同一组。所以我写了这个循环(参见下面的cf),但我想知道是否有一种更像熊猫/蟒蛇的方式来用apply或理解列表来写它Python 添加一列,该列为满足另一列上条件的每个索引递增,python,pandas,Python,Pandas,我试图从数据帧生成一列,以作为分组的基础。我知道非NaN列下的每个NaN列都属于同一组。所以我写了这个循环(参见下面的cf),但我想知道是否有一种更像熊猫/蟒蛇的方式来用apply或理解列表来写它 import pandas >>> DF = pandas.DataFrame([134, None, None, None, 129374, None, None, 12, None], columns=['Val']) >>
import pandas
>>> DF = pandas.DataFrame([134, None, None, None, 129374, None, None, 12, None],
columns=['Val'])
>>> a = [0]
>>> for i in DF['Val']:
if i > 1:
a.append(a[-1] + 1)
else:
a.append(a[-1])
>>> a.pop(0) # remove 1st 0 which does not correspond to any rows
>>> DF['Group'] = a
>>> DF
Val Group
0 134.0 1
1 NaN 1
2 NaN 1
3 NaN 1
4 129374.0 2
5 NaN 2
6 NaN 2
7 12.0 3
8 NaN 3
用于标识非NaN值。然后使用创建组
列:
import pandas as pd
df = pd.DataFrame([134, None, None, None, 129374, None, None, 12, None],
columns=['Val'])
df['Group'] = pd.notnull(df['Val']).cumsum()
print(df)
屈服
Val Group
0 134.0 1
1 NaN 1
2 NaN 1
3 NaN 1
4 129374.0 2
5 NaN 2
6 NaN 2
7 12.0 3
8 NaN 3
用于标识非NaN值。然后使用创建组
列:
import pandas as pd
df = pd.DataFrame([134, None, None, None, 129374, None, None, 12, None],
columns=['Val'])
df['Group'] = pd.notnull(df['Val']).cumsum()
print(df)
屈服
Val Group
0 134.0 1
1 NaN 1
2 NaN 1
3 NaN 1
4 129374.0 2
5 NaN 2
6 NaN 2
7 12.0 3
8 NaN 3