如何從我的數據中的geojson列中提取經度，緯度

Question

我有一個csv文件中的數據，該文件包含1列中的zipcode和另一列中可能包含geojson數據。我在熊貓數據框中加載數據。我如何從geojson列中提取座標。

zips.head(2) 

Out[14]: 
    postal_code geojson 
    0 85309 {"type":"MultiPolygon","coordinates":[[[[-112.... 
    1 85310 {"type":"MultiPolygon","coordinates":[[[[-112.... 


zips.geojson[1] 

zips.geojson.values[0] 

'{"type":"MultiPolygon","coordinates":[[[[-112.363501,33.551312],[-112.363457,33.551312],[-112.36253,33.551309],[-112.361378,33.551311],[-112.360977,33.55131],[-112.358913,33.551305],[-112.358916,33.551104],[-112.358898,33.550758],[-112.358825,33.549401],[-112.358763,33.548056],[-112.358652,33.546016],[-112.358635,33.54554],[-112.358629,33.545429],[-112.358613,33.545143],[-112.358607,33.545039],[-112.358599,33.544897],[-112.358596,33.544838],[-112.358592,33.54478],[-112.358545,33.543923],[-112.358475,33.542427],[-112.358444,33.541913],[-112.35842,33.541399],[-112.358363,33.540373],[-112.358345,33.540104],[-112.35833,33.539878],[-112.35828,33.538863],[-112.358263,33.538352],[-112.358204,33.537335],[-112.358196,33.536892],[-112.358193,33.536444],[-112.358192,33.53631],[-112.358182,33.536031],[-112.358175,33.535797],[-112.358186,33.534197],[-112.358187,33.53324],[-112.358185,33.53278],[-112.358182,33.532218],[-112.358168,33.530732],[-112.358163,33.530174],[-112.35815,33.529797],[-112.359343,33.529819],[-112.359387,33.529812],[-112.359354,33.529716],[-112.360874,33.529732],[-112.370575,33.529805],[-112.375373,33.529907],[-112.37537,33.528961],[-112.375382,33.527693],[-112.375384,33.527033],[-112.375393,33.526355],[-112.374883,33.526353],[-112.371535,33.52634],[-112.366678,33.526323],[-112.366665,33.523201],[-112.366664,33.52285],[-112.366661,33.522734],[-112.366658,33.522596],[-112.366657,33.522553],[-112.366655,33.522502],[-112.366658,33.522388],[-112.368754,33.522441],[-112.370106,33.522618],[-112.370917,33.522624],[-112.371875,33.522633],[-112.371865,33.522389],[-112.371875,33.522162],[-112.37175,33.51916],[-112.375186,33.519096],[-112.375306,33.519094],[-112.375305,33.51971],[-112.375309,33.519728],[-112.375351,33.521607],[-112.375367,33.522304],[-112.375426,33.522419],[-112.375587,33.522423],[-112.375767,33.522426],[-112.382694,33.522547],[-112.382697,33.522654],[-112.382698,33.522709],[-112.382714,33.523282],[-112.382958,33.523283],[-112.383939,33.52329],[-112.383935,33.523153],[-112.386882,33.523097],[-112.38781,33.523781],[-112.38801,33.523609],[-112.388673,33.523001],[-112.388794,33.522895],[-112.388852,33.522844],[-112.389115,33.522837],[-112.389205,33.522761],[-112.389319,33.522661],[-112.392416,33.51994],[-112.392509,33.519195],[-112.392516,33.51914],[-112.401093,33.51914],[-112.401098,33.519779],[-112.401098,33.519838],[-112.401137,33.519885],[-112.401146,33.519903],[-112.40124,33.520001],[-112.401311,33.520066],[-112.401432,33.520158],[-112.401754,33.520412],[-112.402133,33.520685],[-112.402411,33.520892],[-112.402552,33.52098],[-112.402692,33.521087],[-112.402882,33.521256],[-112.402948,33.52133],[-112.403016,33.521428],[-112.403062,33.521517],[-112.4031,33.521621],[-112.40312,33.521715],[-112.403129,33.521822],[-112.403119,33.521937],[-112.403102,33.522011],[-112.403064,33.522109],[-112.403009,33.522208],[-112.402908,33.522336],[-112.402781,33.522475],[-112.402685,33.52257],[-112.402641,33.522613],[-112.402553,33.522692],[-112.401659,33.523488],[-112.401228,33.52388],[-112.401157,33.523961],[-112.401123,33.524028],[-112.401107,33.524102],[-112.401108,33.524213],[-112.401116,33.525097],[-112.401119,33.5263],[-112.401119,33.52634],[-112.401119,33.526441],[-112.399658,33.52646],[-112.399258,33.526743],[-112.395079,33.52973],[-112.394771,33.529977],[-112.39013,33.534207],[-112.388661,33.535533],[-112.385957,33.538011],[-112.384107,33.539698],[-112.384007,33.539732],[-112.383947,33.539786],[-112.38381,33.539862],[-112.384585,33.551063],[-112.384605,33.551372],[-112.384609,33.551434],[-112.384614,33.551508],[-112.384416,33.551505],[-112.38385,33.551499],[-112.38131,33.551461],[-112.380126,33.551454],[-112.378928,33.551432],[-112.376262,33.551405],[-112.373858,33.551381],[-112.372583,33.551378],[-112.370038,33.551354],[-112.368768,33.55135],[-112.367585,33.551339],[-112.36749,33.551338],[-112.363501,33.551312]]]]}' 

我試圖用它的方式，我會在字典中使用值，但我無法對它。

Answer 1

這可能有幫助。它沒有經過測試，所以它可能無法正常工作，或者可能需要針對您的用例略微調整。

這一計劃的重要特點是：

• 使用json.loads()一個JSON字符串轉換爲Python數據結構

• 根據GeoJSON的標準分解數據結構。

參考：

• http://geojson.org/geojson-spec.html#multipolygon

 

#UNTESTED 
import json 

# For every zipcode, print the X position of the first 
# coordinate of the exterior of the multipolygon associated 
# with that zip code 

for zipcode, geo in zips: 
    geo = json.loads(geo) 
    assert geo["type"] == "MultiPolygon" 

    # Coordinates of a MultiPolygon are an array of Polygon coordinate arrays 
    array_of_polygons = geo["coordinates"] 
    polygon0 = array_of_polygons[0] 

    # Coordinates of a Polygon are an array of LinearRing coordinate arrays 
    ring0 = polygon0[0] 

    # A LinearRing is a closed LineString with 4 or more positions 
    # A LineString is an array of positions 
    vertex0 = ring0[0] 

    # A position is represented by an array of numbers. 
    x0 = vertex0[0] 

    print zipcode, x0 

Answer 2

您可以import json和應用json.loads字符串數據在geojson列轉換爲dict。然後，您可以直接從dict提取數據，或者使用處理GIS數據的許多Python模塊之一。我發現shapely易於使用，並在許多情況下有幫助。