NoData issue

[iferencik]

i am reading a COG and upon opening I am getting the following error

async with COGReader(cog_url) as cog:
    print(cog.nodata)

Traceback (most recent call last): File "/work/py/hrea-zarr/pipeline/core.py", line 54, in <module> asyncio.run( File "/usr/lib/python3.8/asyncio/runners.py", line 44, in run return loop.run_until_complete(main) File "/usr/lib/python3.8/asyncio/base_events.py", line 616, in run_until_complete return future.result() File "/work/py/hrea-zarr/pipeline/core.py", line 13, in read_cog print(cog.nodata) File "/work/python/aiocogeo/aiocogeo/cog.py", line 278, in nodata return self.ifds[0].nodata File "/work/python/aiocogeo/aiocogeo/ifd.py", line 167, in nodata return int(self.NoData.value[0]) if self.NoData else None ValueError: invalid literal for int() with base 10: b'-'

upon a closer lock, the code is trying to convert the NoData tag into an int

the self.NoData attr is

Tag(code=42113, name='NoData', count=25, tag_type=TagType(format='c', size=1), length=25, value=(b'-', b'3', b'.', b'3', b'9', b'9', b'9', b'9', b'9', b'9', b'9', b'9', b'9', b'9', b'9', b'9', b'9', b'9', b'9', b'6', b'e', b'+', b'3', b'8', b'\x00'))

which is a tuple of 1 character bytes objects

Now I am not sure whether the COG file is wrong or aiocogeo is not reading this correctly.
A quick solution that could fix this :

        try:
            return int(b''.join(self.NoData.value).strip(b'\x00')) if self.NoData else None
        except ValueError:
            return float(b''.join(self.NoData.value).strip(b'\x00')) if self.NoData else None

This basically strips the zero terminated string and tries to convert it into an int and then float number.

[KeynesYouDigIt]

Is there an example file you can point to? Seems like an easy fix and would love to take a crack at it but would want to be able to test it with the same data currently causing the error. Assuming this isn't occurring for most/all cog files.