1

I wanto to build a function (let's call it clip) that accepts a vector-file (can be a shapefile, a geopackage....) and a raster. How can I make sure the argument that the users gives to the function is a type that for example gepandas can read? I though about something like (completey pseudocode):

def clip(shape, raster):
    if driver(shape) not in geopandas.drivers:
        raise TypeError
    else:
        clip(raster, shape)

I know this is kind of random pseudocode, but maybe some understand what I mean and has an idea.

When I try:


import geopandas

shape = "no_shape.sph"

try:
    shape = geopandas.read_file(shape)
except CPLE_OpenFailedError:
    print("that's not a the path to a vector geometry")
except DriverError:
    print("that's not a valid vector geometry")

I get:

CPLE_OpenFailedError                      Traceback (most recent call last)

fiona/_shim.pyx in fiona._shim.gdal_open_vector()

fiona/_err.pyx in fiona._err.exc_wrap_pointer()

CPLE_OpenFailedError: no_shape.sph: No such file or directory


During handling of the above exception, another exception occurred:

DriverError                               Traceback (most recent call last)

<ipython-input-17-7ed5ed6090fb> in <module>
      5 try:
----> 6     shape = geopandas.read_file(shape)
      7 except CPLE_OpenFailedError:

And I have no idea how to catch that exception and print a message that this is no valid shape (or any other vector supported by geopandas).

  • do you like to check if geopandas can read some kind of file or if the geometries inside the file are valid (e.g. in sense of OGC standards)? – Mesa Jan 25 at 17:02
  • The first part actually. If geopandas can read some kind of file;) – Robin Kohrs Jan 25 at 17:15
2

How about something like this,

try:
    gdf = geopandas.read_file(shape)
except DataIOError as err:
    # log error if you want
    # log(str(err))
    raise TypeError
clip(raster, shape)

Good all try/except

Edit: Just to add some links fiona open doc, geopandas read_file is based on fiona open geopandas io doc.

  • sounds great!! I'll give it a shot:) thanks!! – Robin Kohrs Jan 25 at 18:03

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