python - 如何将 python dict 转换为标准形式的 geojson 文件？

Question

我想将 Excel 文件转换为 geojson 文件。字典是这样的:

[
{"NoAdresse": 42537006584, "NoUsager": 42537000086, "LatEffective": 45.83675, "LongDebut": 4.91956, "LatDebut": 45.75529, "LongEffective": 4.84574, "IdVehicule": "246Veh", "LatArrivee": 45.83492, "NoDemande": 42537000003, "LongArrivee": 4.84762}, 
{"NoAdresse": 42537007718, "NoUsager": 42537002720, "LatEffective": 45.83955, "LongDebut": 4.84574, "LatDebut": 45.83675, "LongEffective": 4.83098, "IdVehicule": "246Veh", "LatArrivee": 45.83935, "NoDemande": 42537000004, "LongArrivee": 4.83084}, 
{"NoAdresse": 42537005803, "NoUsager": 42537002424, "LatEffective": 45.98730, "LongDebut": 4.83098, "LatDebut": 45.83955, "LongEffective": 4.72695, "IdVehicule": "246Veh", "LatArrivee": 45.98174, "NoDemande": 42537000006, "LongArrivee": 4.73942}, 
{"NoAdresse": 42537005803, "NoUsager": 42537003576, "LatEffective": 45.98730, "LongDebut": 4.83098, "LatDebut": 45.83955, "LongEffective": 4.72695, "IdVehicule": "246Veh", "LatArrivee": 45.98174, "NoDemande": 42537000005, "LongArrivee": 4.73942}, 
{"NoAdresse": 42537004215, "NoUsager": 42537003576, "LatEffective": 45.93778, "LongDebut": 4.72695, "LatDebut": 45.9873, "LongEffective": 4.62676, "IdVehicule": "246Veh", "LatArrivee": 45.93784, "NoDemande": 42537000005, "LongArrivee": 4.62625}, 
{"NoAdresse": 42537004215, "NoUsager": 42537002424, "LatEffective": 45.93778, "LongDebut": 4.72695, "LatDebut": 45.9873, "LongEffective": 4.62676, "IdVehicule": "246Veh", "LatArrivee": 45.93784, "NoDemande": 42537000006, "LongArrivee": 4.62625}, 
{"NoAdresse": 42537004215, "NoUsager": 42537002720, "LatEffective": 45.93778, "LongDebut": 4.72695, "LatDebut": 45.9873, "LongEffective": 4.62676, "IdVehicule": "246Veh", "LatArrivee": 45.93784, "NoDemande": 42537000004, "LongArrivee": 4.62625}, 
{"NoAdresse": 42537004215, "NoUsager": 42537000086, "LatEffective": 45.93778, "LongDebut": 4.72695, "LatDebut": 45.9873, "LongEffective": 4.62676, "IdVehicule": "246Veh", "LatArrivee": 45.93784, "NoDemande": 42537000003, "LongArrivee": 4.62625}, 
{"NoAdresse": 42537000007, "NoUsager": 42537002425, "LatEffective": 45.72941, "LongDebut": 4.77845, "LatDebut": 45.77335, "LongEffective": 4.88396, "IdVehicule": "164Veh", "LatArrivee": 45.72815, "NoDemande": 42537000070, "LongArrivee": 4.88241}, 
{"NoAdresse": 42537000007, "NoUsager": 42537002425, "LatEffective": 45.69349, "LongDebut": 4.88396, "LatDebut": 45.72941, "LongEffective": 4.94466, "IdVehicule": "164Veh", "LatArrivee": 45.69429, "NoDemande": 42537000070, "LongArrivee": 4.94216}]

我使用这段代码来实现这一点:

import json

from xlrd import open_workbook

book = open_workbook('forum.xlsx')
sheet = book.sheet_by_index(0)

keys = [sheet.cell(0,col_index).value for col_index in xrange(sheet.ncols)]

dict_list = []
for row_index in xrange(1,sheet.nrows):
    d = {keys[col_index]: sheet.cell(row_index,col_index).value
        for col_index in xrange(sheet.ncols)}
    dict_list.append(d)

j = json.dumps(dict_list)

with open('data.json','w') as f:
    f.write(j)

然后我想将其放入以下形式的 geojson 文件中:

{ "type": "FeatureCollection",
"features": [{ 
    "type": "Feature",
    "geometry": {
        "type": "LineString",
        "coordinates": [[LatDebut, LongDebut],[LatEffective,LongEffective]]
    },
    "properties": {
        "NoAdresse": "XXX",
        "NoUsager": "XXX",
        "NoDemand":"XXX",
        "IdVehicule":"XXX"
    }
}, { 
...
}]
}

我不知道该怎么做，也不知道是否有另一种方法可以直接从 Excel 转换为 geojson 文件。此外，我想添加一个属性“Tour”，每次“IdVehicle”更改时它都会更改。我知道这个要求太多了，但我被困了这么久，任何帮助将不胜感激。

谢谢

Answer 1

因此，如果您知道如何将字典“按摩”到您想要的最终结构中 - 将所有“其他元素”移动到某些属性成员中 - 那么我认为它就像

# work on dict_list to produce some dict_in_geojson_form
# ... then:
with open('data.json','w') as f:
    json.dump(dict_in_geojson_form, f)

如果序列化仍然不清楚，您可能还想看看 Python dump dict to json file或How do I write JSON data to a file in Python? ...

高级更新:根据修改后的请求进行一些简单的转换并添加了游览枚举。请参阅下面的示例代码(拆分在不同的代码框中，以便不必滚动...:

#! /usr/bin/env python
"""Map a specific stream to seom GeoJSON target structure and stream the
output in chunks as elements are complete (any new vehicle id increments
the tour label which works like an enumeration in the properties of the
features GeoJSON representation)."""
from __future__ import print_function

import copy
import json
import sys

# 一些限制文字和准备结构的声明

NO_ADDRESS = 'NoAdresse'
NO_USAGE = 'NoUsager'
ID_VEHICLE = 'IdVehicule'
NO_DEMAND = 'NoDemande'

TOUR_LABEL = 'Tour'

PROPERTY_KEYS = (NO_ADDRESS, NO_USAGE, ID_VEHICLE, NO_DEMAND)

LAT_DEBUT = 'LatDebut'
LONG_DEBUT = 'LongDebut'
LAT_EFFECTIVE = 'LatEffective'
LONG_EFFECTIVE = 'LongEffective'

COORD_KEYS_DEBUT = (LAT_DEBUT, LONG_DEBUT)
COORD_KEYS_EFFECTIVE = (LAT_EFFECTIVE, LONG_EFFECTIVE)

PROPERTIES_KEY = 'properties'
GEOMETRY_KEY = 'geometry'
COORDINATES_KEY = 'coordinates'
FEATURES_KEY = 'features'

GEOJSON_FRAME_PREFIX = """{
"type": "FeatureCollection",
"features": [
"""

FEATURE_TEMPLATE = {
    "type": "Feature",
    GEOMETRY_KEY: {
        "type": "LineString",
        "coordinates": []
    },
    "properties": {
        NO_ADDRESS: None,
        NO_USAGE: None,
        NO_DEMAND: None,
        ID_VEHICLE: None,
        TOUR_LABEL: None
    }}

GEOJSON_LIST_SEP = ',\n'
GEOJSON_FRAME_POSTFIX = ']\n}\n'

# 一个简单的功能发射源模拟

def event_source():
    """Sample input line source generator. Might anything yielding
    python dictionaries matching "this questions" event specification."""

    event_seq = [
        {NO_ADDRESS: 42537006584, NO_USAGE: 42537000086,
         LAT_EFFECTIVE: 45.83675, LONG_DEBUT: 4.91956,
         LAT_DEBUT: 45.75529, LONG_EFFECTIVE: 4.84574,
         ID_VEHICLE: "246Veh", "LatArrivee": 45.83492,
         NO_DEMAND: 42537000003, "LongArrivee": 4.84762},
        {NO_ADDRESS: 42537007718, NO_USAGE: 42537002720,
         LAT_EFFECTIVE: 45.83955, LONG_DEBUT: 4.84574,
         LAT_DEBUT: 45.83675, LONG_EFFECTIVE: 4.83098,
         ID_VEHICLE: "246Veh", "LatArrivee": 45.83935,
         NO_DEMAND: 42537000004, "LongArrivee": 4.83084},
        # ...
        {NO_ADDRESS: 42537000007, NO_USAGE: 42537002425,
         LAT_EFFECTIVE: 45.69349, LONG_DEBUT: 4.88396,
         LAT_DEBUT: 45.72941, LONG_EFFECTIVE: 4.94466,
         ID_VEHICLE: "164Veh", "LatArrivee": 45.69429,
         NO_DEMAND: 42537000070, "LongArrivee": 4.94216}]

    for event in event_seq:
        yield event

# 上下文无关转换:

def feature_from(event):
    """Transform event to feature, applying the "business" rules."""
    feature = copy.deepcopy(FEATURE_TEMPLATE)
    for property_key in PROPERTY_KEYS:
        feature[PROPERTIES_KEY][property_key] = event[property_key]
    coords_debut = [event[k] for k in COORD_KEYS_DEBUT]
    coords_effective = [event[k] for k in COORD_KEYS_EFFECTIVE]
    feature[GEOMETRY_KEY][COORDINATES_KEY].append(coords_debut)
    feature[GEOMETRY_KEY][COORDINATES_KEY].append(coords_effective)
    return feature

# 功能的分离发射器(这里太过分了，但是......)

def feature_gen(events):
    """Generator creates features from events (might be a good place
    to hook into validty checks in real lif processing)."""
    for event in events:
        yield feature_from(event)

# 共享游览的特征序列的上下文感知生成器

def tour_gen(features):
    """Generator emits the feature in chunks per complete tour as detected
    by a change in vehicle id."""
    id_vehicle_active = None
    tour_enumeration = None
    for feature in features:
        id_vehicle_received = feature[PROPERTIES_KEY][ID_VEHICLE]
        if id_vehicle_active is None:
            id_vehicle_active = id_vehicle_received
            tour_enumeration = 1
            tour = []
        if id_vehicle_active != id_vehicle_received:
            yield tour
            tour = []
            tour_enumeration += 1
            id_vehicle_active = id_vehicle_received
            feature[PROPERTIES_KEY][TOUR_LABEL] = tour_enumeration
            tour.append(feature)
        else:
            feature[PROPERTIES_KEY][TOUR_LABEL] = tour_enumeration
            tour.append(feature)
    if tour:
        yield tour

# 模拟函数将输出引导到 stdout 或文件...

def geojson_out(text, stream=sys.stdout):
    """Expected JSON text is output here."""
    stream.write(text)

# 驱动转换的示例处理逻辑

def main():
    """Poor man's streaming falls back on hardcoded GeoJSON "frame"
    string as pre and post fix to the feature stream. the latter
    elements are accumulated in chunks carrying common "tour"
    enumeration label.

    The frame structure in Python lingo is:
        geo_dict = {"type": "FeatureCollection", "features": []}

    The features will be injected in the list and in this implementation
    need some stateful separator injection hack, to yield valid JSON
    (which does not allow trailing comma after last array elememt).
    """

# ...此处作为写入硬编码文件路径的示例

    with open('yumyum.geojson', 'wt') as f_out:
        geojson_out(GEOJSON_FRAME_PREFIX, stream=f_out)
        json_array_nanny_needed = False  # Semi-auto, means semi-manual =(
        for features in tour_gen(feature_gen(event_source())):
            for feature in features:
                if json_array_nanny_needed:
                    geojson_out(GEOJSON_LIST_SEP, stream=f_out)
                geojson_out(json.dumps(feature, sort_keys=True), stream=f_out)
                json_array_nanny_needed = True  # HACK A DID ACK

        geojson_out(GEOJSON_FRAME_POSTFIX, stream=f_out)

if __name__ == '__main__':
    main()

处理的想法应该在文档字符串中......

人们还可以收集/聚合/过滤每个车辆 ID 的坐标，或者......它是 Python 一种通用编程语言;-)

在我的机器上 yumyum.txt 内的输出是:

$ cat yumyum.geojson 
{
"type": "FeatureCollection",
"features": [
{"geometry": {"coordinates": [[45.75529, 4.91956], [45.83675, 4.84574]], "type": "LineString"}, "properties": {"IdVehicule": "246Veh", "NoAdresse": 42537006584, "NoDemande": 42537000003, "NoUsager": 42537000086, "Tour": 1}, "type": "Feature"},
{"geometry": {"coordinates": [[45.83675, 4.84574], [45.83955, 4.83098]], "type": "LineString"}, "properties": {"IdVehicule": "246Veh", "NoAdresse": 42537007718, "NoDemande": 42537000004, "NoUsager": 42537002720, "Tour": 1}, "type": "Feature"},
{"geometry": {"coordinates": [[45.72941, 4.88396], [45.69349, 4.94466]], "type": "LineString"}, "properties": {"IdVehicule": "164Veh", "NoAdresse": 42537000007, "NoDemande": 42537000070, "NoUsager": 42537002425, "Tour": 2}, "type": "Feature"}]
}