[NumPy-Tickets] [NumPy] #1071: loadtxt fails if the last column contains empty value
NumPy Trac
numpy-tickets@scipy....
Thu Mar 31 12:10:05 CDT 2011
#1071: loadtxt fails if the last column contains empty value
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Reporter: Electrion | Owner: somebody
Type: defect | Status: needs_review
Priority: normal | Milestone: 1.6.0
Component: numpy.lib | Version: devel
Keywords: loadtxt ascii strip |
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Comment(by bsouthey):
Replying to [comment:4 derek]:
> I am afraid I don't understand how this pertains to the ticket.
I want to keep a distinction between loadtxt and genfromtxt. Specifically
genfromtxt was added in 2009 especially to address many of the limitations
of loadtxt (added in 2007). So we need to avoid adding new
features/abilities to loadtxt that duplicate features already present in
genfromtxt.
The ticket says 'empty value' which means 'missing data'. My response is
that loadtxt must fail in such cases because the loadtxt docstring clearly
states that in 3 different, yet critical places, that missing values are
not handled:
Each row in the text file must have the same number of values.
genfromtxt : Load data with missing values handled as specified.
This function aims to be a fast reader for simply formatted files. The
genfromtxt function provides more sophisticated handling of, e.g., lines
with missing values.
Really the ticket and your last example arise from the ''misused'' of
loadtxt features (i.e. converters) to handle missing data. But since
loadtxt is not meant to handle missing values, the ticket and your example
is invalid. If missing values were allowed then sure there is a problem.
The attached patch would still be incorrect because it should not include
the space in the strip. However I am not sure if similar cases will be
uncovered (like more than one delimiter in certain lines) or that really
the split_line function should be changed so it first splits valid lines
on the delimiter.
--
Ticket URL: <http://projects.scipy.org/numpy/ticket/1071#comment:6>
NumPy <http://projects.scipy.org/numpy>
My example project
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