如何将行合并为单独的数据框python熊猫

问题描述

我有以下数据集：

import pyspark.sql.functions as f

df2 = df.withColumn('len',f.substring('Length',15,10))
df2.show(10,False)

+----------------------------------------------------+----+----------+
|Length                                              |ID  |len       |
+----------------------------------------------------+----+----------+
|+++++++++++++++++++++++++XXXXX++++++++++++++XXXXXXXX|1.0 |++++++++++|
|XXXXXX++++++++++++XXXXXX+++++++++++++++XXXXXXXXXXXXX|2.0 |++++XXXXXX|
|++++++++++++++++++XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX|3.0 |++++XXXXXX|
|XXXXXXXXXXXXXX++++++++++++++++++++XXXXXXXXXXXXXXXXXX|4.0 |++++++++++|
|+++++++++++++++++++++++++XXXXXXXXXXXXXXXXXXXXXXXXXXX|5.0 |++++++++++|
|+++++++++++++++++++++++++XXXXX++++++++++++++XXXXXXXX|6.0 |++++++++++|
|XXXXXX++++++++++++XXXXXX+++++++++++++++XXXXXXXXXXXXX|7.0 |++++XXXXXX|
|++++++++++++++++++XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX|8.0 |++++XXXXXX|
|XXXXXXXXXXXXXX++++++++++++++++++++XXXXXXXXXXXXXXXXXX|9.0 |++++++++++|
|+++++++++++++++++++++++++XXXXXXXXXXXXXXXXXXXXXXXXXXX|10.0|++++++++++|
+----------------------------------------------------+----+----------+

df2.filter("len = 'XXXXXXXXXX'").show(10,False)

+------+---+---+
|Length|ID |len|
+------+---+---+
+------+---+---+

我想将x y z合并到另一个数据帧中，如下所示：

A           B           C           D   E   F
154.6175111 148.0112337 155.7859835 1   1   x
255 253.960131  242.5382584         1   1   x
251.9665958 235.1105659 185.9121703 1   1   x
137.9974994 225.3985177 254.4420772 1   1   x
85.74722877 116.7060415 158.4608395 1   1   x
123.6969939 140.0524405 132.6798037 1   1   x
133.3251695 80.08976196 38.81201612 1   1   y
118.0718812 243.5927927 255         1   1   y
189.5557302 139.9046713 91.90519519 1   1   y
172.3117291 188.000268  129.8155501 1   1   y
48.07634611 21.9183119  25.99669279 1   1   y
23.40525987 8.395857933 25.62371342 1   1   y
228.753009  164.0697727 172.6624107 1   1   z
203.3405006 173.9368303 189.8103708 1   1   z
184.9801932 117.1591341 87.94739034 1   1   z
29.55251224 46.03945452 70.7433477  1   1   z
143.6159623 120.6170926 155.0736604 1   1   z
142.5421179 128.8916843 169.6013111 1   1   z

我希望每个x y z值都具有这些数据帧，例如第一，第二，第三等等。

我如何选择和组合它们？

所需的输出：

A           B           C           D   E   F
154.6175111 148.0112337 155.7859835 1   1   x  ->first x value
133.3251695 80.08976196 38.81201612 1   1   y  ->first y value
228.753009  164.0697727 172.6624107 1   1   z  ->first z value

解决方法

使用GroupBy.cumcount作为计数器，然后由另一个groupby对象循环：

g = df.groupby('F').cumcount()

for i,g in df.groupby(g):
    print (g)