numpy.genfromtxt raises StopIteration error on empty file

[ambersaw]

I'm processing a number of csvs in a single script, and sometimes csvs will be empty, which causes a StopIteration exception. This is not serious, but I think it would be helpful if one or more of the following happened:

1. This simply be documented: people should know that this happens so they can wrap the section in a try catch block
2. The exception should be caught and re-passed with a more intuitive name, something like InvalidFile
3. A new flag should be added/old flag expanded to optionally silence the exception and return an empty array

Reproducing code example:

import numpy as np
import os
inFile = "/tmp/example.csv"
os.system(f"touch {inFile}")
my_data = np.genfromtxt(inFile, delimiter=',', skip_header=1, invalid_raise=false)

Error message:

Traceback (most recent call last):
File "", line 1, in
File "/#####/lib/python3.6/site-packages/numpy/lib/npyio.py", line 1780, in genfromtxt
next(fhd)
StopIteration

Numpy/Python version information:

1.17.0 3.6.3 (default, Apr 24 2018, 18:36:28)
[GCC 4.7.2]

[maxwell-aladago]

When skip_header=0, the error message returned is actually issues a UserWarning that file is empty and returns an empty list. skip_footer too returns the warning and an empty list. I agree with you that, maybe, it should behave the same way even when skip_header > 0. Although asking that a header be skipped does assume that the file isn't empty.