假设我有一个如下数据框：
FDT_DATE FFLT_LATITUDE FFLT_LONGITUDE FINT_STAT FSTR_ID
51307 1417390467000 31.2899 121.4845 0 112609
51308 1417390428000 31.2910 121.4859 0 112609
51309 1417390608000 31.2944 121.4857 1 112609
51310 1417390548000 31.2940 121.4850 1 112609
51313 1417390668000 31.2954 121.4886 1 112609
51314 1417390717000 31.2965 121.4937 1 112609
53593 1417390758000 31.2946 121.4940 0 112609
63586 1417390798000 31.2932 121.4960 1 112609
63587 1417390818000 31.2940 121.4966 1 112609
63588 1417390827000 31.2946 121.4974 1 112609
63589 1417390907000 31.2952 121.4986 0 112609
我想在折线列表中提取位置记录，意味着提取具有相同FSTR_ID且FINT_STAT等于1的记录的位置：
FSTR_ID FDT_DATE POLYLINE
0 112609 1417390608000 [[31.2944,121.4857],[31.2940,121.4850],[31.2954,121.4886],[31.2965,121.4937]]
1 112609 1417390798000 [[31.2932,121.4960],[31.2940,121.4966],[31.2946, 121.4974]]
我该怎么做？
原始数据集可以通过以下代码生成：
import pandas as pd
df = pd.DataFrame({"FDT_DATE":{"0":1417390467000,"1":1417390428000,"2":1417390608000,"3":1417390548000,"4":1417390668000,"5":1417390717000,"6":1417390758000,"7":1417390798000,"8":1417390818000,"9":1417390827000,"10":1417390907000},"FFLT_LATITUDE":{"0":31.2899,"1":31.291,"2":31.2944,"3":31.294,"4":31.2954,"5":31.2965,"6":31.2946,"7":31.2932,"8":31.294,"9":31.2946,"10":31.2952},"FFLT_LONGITUDE":{"0":121.4845,"1":121.4859,"2":121.4857,"3":121.485,"4":121.4886,"5":121.4937,"6":121.494,"7":121.496,"8":121.4966,"9":121.4974,"10":121.4986},"FINT_STAT":{"0":0,"1":0,"2":1,"3":1,"4":1,"5":1,"6":0,"7":1,"8":1,"9":1,"10":0},"FSTR_ID":{"0":112609,"1":112609,"2":112609,"3":112609,"4":112609,"5":112609,"6":112609,"7":112609,"8":112609,"9":112609,"10":112609}})
df = df.sort(['FDT_DATE'])
答案 0 :(得分：2)
import pandas as pd
import numpy as np
# Initializing the data
df = pd.DataFrame({'FDT_DATE': {0: 1417390467000, 1: 1417390428000, 2: 1417390608000, 3: 1417390548000,
4: 1417390668000, 5: 1417390717000, 6: 1417390758000, 7: 1417390798000,
8: 1417390818000, 9: 1417390827000, 10: 1417390907000},
'FFLT_LATITUDE': {0: 31.2899, 1: 31.291, 2: 31.2944, 3: 31.294, 4: 31.2954,
5: 31.2965, 6: 31.2946, 7: 31.2932, 8: 31.294, 9: 31.2946,
10: 31.2952},
'FFLT_LONGITUDE': {0: 121.4845, 1: 121.4859, 2: 121.4857, 3: 121.485, 4: 121.4886,
5: 121.4937, 6: 121.494, 7: 121.496, 8: 121.4966, 9: 121.4974,
10: 121.4986},
'FINT_STAT': {0: 0, 1: 0, 2: 1, 3: 1, 4: 1, 5: 1, 6: 0, 7: 1, 8: 1, 9: 1,
10: 0},
'FSTR_ID': {0: 112609, 1: 112609, 2: 112609, 3: 112609, 4: 112609, 5: 112609,
6: 112609, 7: 112609, 8: 112609, 9: 112609, 10: 112609}})
# Transforming sequences of records with FINT_STAT == 1 to unique GROUP_ID values
df['GROUP_ID'] = df['FINT_STAT'].apply(np.logical_not).cumsum()
# Marking groups with FINT_STAT == 0 for removing
df['GROUP_ID'] *= df['FINT_STAT']
# Removing marked groups
df['GROUP_ID'] = df['GROUP_ID'].replace(0, np.NaN)
# Grouping by columns GROUP_ID and FSTR_ID
gb = df.groupby(['GROUP_ID', 'FSTR_ID'])
result = pd.DataFrame()
# Appending columns with values of minimal FDT_DATE for every group
result['MIN_FDT_DATE'] = gb['FDT_DATE'].min()
# Aggregating results by applying the lambda
# which return list of pairs of FFLT_LATITUDE and FFLT_LONGITUDE
result['COORDINATES'] = gb.apply(lambda group: [(row['FFLT_LATITUDE'], row['FFLT_LONGITUDE'])
for _, row in group.iterrows()])
# Widening line and max column width for printing
pd.set_option('display.line_width', 300)
pd.set_option('display.max_colwidth', 200)
# Looking at result
print (result)
输出：
MIN_FDT_DATE COORDINATES
GROUP_ID FSTR_ID
2.0 112609 1417390548000 [(31.2944, 121.4857), (31.294, 121.485), (31.2954, 121.4886), (31.2965, 121.4937)]
3.0 112609 1417390798000 [(31.2932, 121.496), (31.294, 121.4966), (31.2946, 121.4974)]
答案 1 :(得分：1)
list方法将 You can insert pandas.DataFrame()加入.set_value()。列类型应为object。
df = pd.DataFrame({"FDT_DATE":[1417390467000, 1417390428000, 1417390608000, 1417390548000,
1417390668000, 1417390717000, 1417390758000, 1417390798000, 1417390818000,
1417390827000, 1417390907000], "FFLT_LATITUDE":[31.2899, 31.291, 31.2944, 31.294,
31.2954, 31.2965, 31.2946, 31.2932, 31.294, 31.2946, 31.2952],
"FFLT_LONGITUDE":[121.4845, 121.4859, 121.4857, 121.485, 121.4886, 121.4937,
121.494, 121.496, 121.4966, 121.4974, 121.4986],
"FINT_STAT":[0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0],
"FSTR_ID":[112609, 112609, 112609, 112609, 112609, 112609, 112609, 112609,
112609, 112609, 112609]})
df = df.sort(['FDT_DATE']).reset_index(drop=True).reset_index()
def func(x):
global a
global b
if (x['index'] - x['FINT_STAT']) != x['index']:
return a
else:
b += 1
a = b
# Create 't1' column for filter "1" groups in 'FINT_STAT' column
a = 0
b = 0
df['t1'] = df[['index', 'FINT_STAT']].apply(lambda x: func(x), axis=1)
# Initialize result dataframe
df_res = df.drop_duplicates(subset=['t1'])[['FSTR_ID', 'FDT_DATE', 't1']].copy()\
.reset_index(drop=True)
df_res = df_res.dropna().reset_index(drop=True)
# First create 'POLYLINE' column then convert it into 'object'
df_res['POLYLINE'] = np.nan
df_res['POLYLINE'] = df_res['POLYLINE'].astype(object)
# Inserting list into dataframe is available with 'pd.DataFrame.set_value()
for i in df['t1'].dropna().unique():
df_res.set_value(df_res.loc[df_res['t1'] == i, 't1'].index.tolist()[0], 'POLYLINE',
df.loc[df['t1'] == i, ['FFLT_LATITUDE', 'FFLT_LONGITUDE']].values.tolist())
df_res = df_res.drop(['t1'], axis=1)
结果是（您的发布结果未按'FDT_DATE'排序）：
FSTR_ID FDT_DATE POLYLINE
0 112609 1417390548000 [[31.294, 121.485], [31.2944, 121.4857], [31.2954, 121.4886], [31.2965, 121.4937]]
1 112609 1417390798000 [[31.2932, 121.496], [31.294, 121.4966], [31.2946, 121.4974]]