Question

我的摘要统计结果的结果包含以下列：

TOWN
SETTLEMENTNAME
NAME
TIME
FREQUENCY

我使用Python Pandas和NumPy编写了以下代码：

'''
Created on April 6, 2016

Summarise Number of Buildings

per Time Interval

(5, 10, 15, 25, 30, 60)

@author: PeterW
'''
# import site-packages and modules
from pathlib import Path
import numpy.lib.recfunctions as rfn
import pandas as pd  # Pandas version 0.13.0
import arcpy

# set arguments
saa_stats_table = r"E:\Projects\2016\G112224\Models\Schools\Schools_Combined_160505.gdb\Botrivier_Prim_SAA_Stats"

# environment settings
arcpy.env.overwriteOutput = True
fgdb = Path(saa_stats_table).parents[0]


def pivot_table(saa_stats_table, fgdb):
    fields = [f.name for f in arcpy.ListFields(saa_stats_table)]
    table_recarray = arcpy.da.TableToNumPyArray(saa_stats_table, fields)  # @UndefinedVariable
    print table_recarray
    df = pd.DataFrame(table_recarray[fields])
    pivot = df.pivot(index="OBJECTID",
                     columns="TIME",
                     values="FREQUENCY").fillna(0, downcast="infer")
    pivot_fields = pivot.columns.values
    # rename pivot fields with prefix "TIME"
    pivot.columns = [("{0}{1}".format("TIME", field)) for field in pivot_fields]
    # convert pandas dataframe to record array
    pivot_recarray = pivot.to_records(index=False)
    pivot_type = pivot_recarray.dtype.descr
    pivot_type_new = [(x[0], x[1].replace(x[1], "<i2")) for x in pivot_type]
    # change pivot record array data type to short integer
    pivot_recarray = pivot_recarray.astype(pivot_type_new)
    fields2 = ["TOWN", "SETTLEMENTNAME", "NAME"]
    table_type_new = [(str(x), "<U25") for x in fields2]
    # change table array data type to unicode 50 characters
    table_recarray = table_recarray[fields2].astype(table_type_new)
    recarray_list = [table_recarray, pivot_recarray]
    # merge table and pivot record array
    summary_array = rfn.merge_arrays(recarray_list, flatten=True, usemask=False)
    summary_table = str(Path(fgdb, "SAA_Stats_Test"))
    # convert merged record array to file geodatabase table
    if arcpy.Exists(summary_table):
        arcpy.Delete_management(summary_table)
        arcpy.da.NumPyArrayToTable(summary_array, summary_table)  # @UndefinedVariable
    else:
        arcpy.da.NumPyArrayToTable(summary_array, summary_table)  # @UndefinedVariable

pivot_table(saa_stats_table, fgdb)

我得到的结果是：

我正在寻找的结果是前三列是案例字段的位置，其余的是将TIME5 - TIME 60设置为新列的位置：

我不确定如何折叠前三个字段：＆＃34; TOWN＆＃34;，＆＃34; SETTLEMENTNAME＆＃34;，＆＃34; NAME＆＃34;并拥有＆＃34; TIME＆＃34;设置的字段。任何建议将不胜感激。

Answer 1

您可以根据需要使用.stack()和.unstack()重塑DataFrame。

从df开始：

        TOWN  SETTLEMENT            NAME  TIME5  TIME10  TIME15  TIME20  \
0  Botrivier  New France  Botrivier Prim      0       0       0       0   
1  Botrivier  New France  Botrivier Prim      0       0       0     100   

   TIME25  TIME30  TIME60  
0     200       0       0  
1       0       0       0

您可以使用.stack()

df = df.set_index(['TOWN', 'SETTLEMENT', 'NAME']).stack()

产生：

TOWN       SETTLEMENT  NAME                  
Botrivier  New France  Botrivier Prim  TIME5       0
                                       TIME10      0
                                       TIME15      0
                                       TIME20      0
                                       TIME25    200
                                       TIME30      0
                                       TIME60      0
                                       TIME5       0
                                       TIME10      0
                                       TIME15      0
                                       TIME20    100
                                       TIME25      0
                                       TIME30      0
                                       TIME60      0

此时，您需要决定如何处理每个案例的多个0值，因为.unstack()不适用于重复的索引值。

一种简单的方法是删除0值，并在必要时添加TIME columns 0值。

df[df!=0].unstack().reset_index()

然后产生：

        TOWN  SETTLEMENT            NAME  TIME20  TIME25
0  Botrivier  New France  Botrivier Prim   100.0   200.0

希望这有帮助。

根据前三列透视列和合并

1 个答案: