将 GeoPandas Multipolygon Dataframe 扩展为每行一个多边形

Question

这个问题类似于另一个问题，但没有一个解决方案对我有用。注意我已经包含了对这些解决方案和结果的几次尝试。如果另一个图书馆能做到这一点，我愿意接受。

我正在尝试使用包含多个多边形的 GeoPandas 扩展 GeoJson 文件。

当前地理数据框（3 行）

fill    fill-opacity    stroke  stroke-opacity  stroke-width    title   geometry
0   #9bf1e2 0.3 #9bf1e2 1   1   Hail Possible   (POLYGON ((-80.69500140880155 22.2885709067316...
1   #08c1e6 0.3 #08c1e6 1   1   Severe Hail (POLYGON ((-103.4850007575523 29.2010260633722...
2   #682aba 0.3 #682aba 1   1   Damaging Hail   (POLYGON ((-104.2750007349772 32.2629245180204...`

所需的地理数据框（200 多行）

fill    fill-opacity    stroke  stroke-opacity  stroke-width    title   geometry
0   #9bf1e2 0.3 #9bf1e2 1   1   Hail Possible   (POLYGON ((-80.69500140880155 22.2885709067316...
1   #9bf1e2 0.3 #9bf1e2 1   1   Hail Possible   (POLYGON ((-102.8150007766983 28.2180513479277...
2   #9bf1e2 0.3 #9bf1e2 1   1   Hail Possible   (POLYGON ((-103.4850007575523 29.0940821135748...
3   #9bf1e2 0.3 #9bf1e2 1   1   Hail Possible   (POLYGON ((-103.5650007552662 30.9947420843694...
4   #9bf1e2 0.3 #9bf1e2 1   1   Hail Possible   (POLYGON ((-103.6150007538374 31.0173836504729...

正在使用的 geojson 文件示例文件：https ://drive.google.com/file/d/1m6cMR4jF3QWp07e23sIdb0UF9xLD062s/view?usp = sharing

我尝试过但没有成功：

df3.set_index(['title'])['geometry'].apply(pd.Series).stack().reset_index()

（返回原始不变的 gdf）

def cartesian(x): 
    return np.vstack(np.array([np.array(np.meshgrid(*i)).T.reshape(-1,7) for i in x.values]))
ndf = pd.DataFrame(cartesian(df3),columns=df3.columns)

（返回原始不变的 gdf）

import geopandas as gpd
from shapely.geometry.polygon import Polygon
from shapely.geometry.multipolygon import MultiPolygon

def explode(indata):
    indf = gpd.GeoDataFrame.from_file(indata)
    outdf = gpd.GeoDataFrame(columns=indf.columns)
    for idx, row in indf.iterrows():
        if type(row.geometry) == Polygon:
            outdf = outdf.append(row,ignore_index=True)
        if type(row.geometry) == MultiPolygon:
            multdf = gpd.GeoDataFrame(columns=indf.columns)
            recs = len(row.geometry)
            multdf = multdf.append([row]*recs,ignore_index=True)
            for geom in range(recs):
                multdf.loc[geom,'geometry'] = row.geometry[geom]
            outdf = outdf.append(multdf,ignore_index=True)
    return outdf

explode(GEOJSONFILE)

（返回原始不变的 gdf）

这是我在这里的第一个问题，所以如果需要任何其他信息或细节，请告诉我。

更新：发现explode() 函数的问题是由于文件的格式问题，其中几何本质上是多多边形的多多边形，导致只有第一个多多边形的循环。爆炸功能有效。

Answer 1

您可以使用 Geopandas explode()。

exploded = original_df.explode()

从文档字符串复制：

    Explode muti-part geometries into multiple single geometries.

    Each row containing a multi-part geometry will be split into
    multiple rows with single geometries, thereby increasing the vertical
    size of the GeoDataFrame.
    The index of the input geodataframe is no longer unique and is
    replaced with a multi-index (original index with additional level
    indicating the multiple geometries: a new zero-based index for each
    single part geometry per multi-part geometry).

    Returns
    -------
    GeoDataFrame
        Exploded geodataframe with each single geometry
        as a separate entry in the geodataframe.