将trj保存成.gpx文件方便进行地图匹配（来自徐博士的支援）

import os
import pandas as pd
import numpy as np

gpx_save_dir = "D:/data/Geolife Trajectories 1.3/Data_gpx"
csv_file_dir = "D:/data/Geolife Trajectories 1.3/Data_csv"
txt_files = os.listdir(csv_file_dir)
col_names = ['lat', 'lon', 'datatime', 'uid']
dtype_dic = {'lat': object, 'lon': object, 'datatime': object, 'uid': str}
for txt in txt_files:
    # print(txt)
    txt_path = os.path.join(csv_file_dir, txt)
    data = pd.read_csv(txt_path, header=None, names=col_names, dtype=dtype_dic)
    data = data.round(decimals=7)

    time = data.datatime.values[0].split(" ")[0]
    userid = np.unique(data.uid.values)[0]
    gpx = txt.split(".")[0] + ".gpx"
    gpx_save_file = os.path.join(gpx_save_dir, gpx)
    f = open(gpx_save_file, 'a')
    f.write("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\" ?>\n"
            "<gpx xmlns=\"http://www.topografix.com/GPX/1/1\" creator=\"Graphhopper\" version=\"1.1\">\n"
            "<metadata>\n"
            "<copyright author=\"OpenStreetMap contributors\"/>\n"
            "<text>GraphHopper GPX</text>\n")
    f.write("<uid>"+userid+"</uid>\n") #要改uid
    f.write("<time>"+time+"T00:00:00+00:00</time>\n") #要改时间
    f.write("</metadata>\n"
            "<trk><name>GraphHopper</name><trkseg>\n")
    fwrite_str = ""
    for i_d in range(data.shape[0]):
        data_row = data.values[i_d]
        lat, lng, datetime, uid = data_row[0], data_row[1], data_row[2], data_row[3]
        lat = '{}'.format(lat)
        lng = '{}'.format(lng)
        ts_str = '{}'.format(datetime)
        ts_str = ts_str.split(" ")
        write_str = "<trkpt lat=\""+lat+"\" lon=\""+lng+"\"><time>"+ts_str[0]+"T"+ts_str[-1]+"+00:00</time></trkpt>\n"
        fwrite_str += write_str
    fwrite_str += "</trkseg></trk></gpx>"
    # print(fwrite_str)
    f.write(fwrite_str)
    f.close()

　　MapMatching 见：本博文---> https://www.cnblogs.com/jeshy/p/14350196.html