如何在 Python 中使用 Geopandas 更改 crs 投影？

Question

我正在尝试将 .crs 从圆柱投影 (WGS84 (lat/lon)) 更改为墨卡托投影。可以在此处找到一些信息 (https://geopandas.org/projections.html)。但是，对于比利时的这个 shapefile，它似乎对我不起作用。（geopandas-website for the world 上的示例运行良好，因此所有库都已正确安装）有人知道问题可能是什么？ -> 对于比利时的这个 shapefile，我的 .crs 保持圆柱形并且不会更改为墨卡托投影。（数据集 'BELGIUM__Municipalities.shp' -> https://hub.arcgis.com/datasets/esribeluxdata::belgium-municipalities-1）

示例代码：

import geopandas
import fiona
import matplotlib.pyplot as plt
import pandas as pd

def records(filename, list):
    list = sorted(list)
    with fiona.open(filename) as source: 
        for i, feature in enumerate(sourceô:max(list)+1):
            if i in list:
                yield feature

a = list(range(588))
municipalities = geopandas.GeoDataFrame.from_features(records("BELGIUM__Municipalities.shp",a))

municipalities.crs = "epsg:4326"  #WGS84(lat/lon)-projection
municipalities.plot(facecolor = 'lightgrey', linewidth = 0.05, edgecolor = 'black', alpha = 0.25)

municipalities.to_crs("epsg:3395") #Mercator-projection
municipalities.plot(facecolor = 'lightgrey', linewidth = 0.05, edgecolor = 'black', alpha = 0.25)

plt.show()

编辑：

import geopandas
import fiona
import matplotlib.pyplot as plt
import pandas as pd

def records(filename, list):
    list = sorted(list)
    with fiona.open(filename) as source: 
        for i, feature in enumerate(sourceô:max(list)+1):
            if i in list:
                yield feature

a = list(range(588))
municipalities = geopandas.GeoDataFrame.from_features(records("BELGIUM__Municipalities.shp",a))

municipalities.crs = "epsg:4326"  #WGS84(lat/lon)-projection
municipalities.plot(facecolor = 'lightgrey', linewidth = 0.05, edgecolor = 'black', alpha = 0.25)

municipalities = municipalities.to_crs("epsg:3395") #Mercator-projection
municipalities.plot(facecolor = 'lightgrey', linewidth = 0.05, edgecolor = 'black', alpha = 0.25)

plt.show()

Answer 1

GeoDataFrame.to_crs() 不会就地重新投影，它 returns 一个新对象。如果你想像这样使用你的代码，你必须将它分配回 municipalities。

municipalities = municipalities.to_crs("epsg:3395") #Mercator-projection

最重要的是，您的绘图代码将不起作用，正确的语法是这样的：

municipalities.plot(facecolor = 'lightgrey', linewidth = 0.05, edgecolor = 'black', alpha = 0.25)

请注意数字中的 . 而不是 ,。

如何在 Python 中使用 Geopandas 更改 crs 投影？

How do I change the crs projection using Geopandas in Python?

python

matplotlib

geopandas

pyproj