[Numpy-discussion] loadtxt stop
Zachary Pincus
zachary.pincus@yale....
Fri Sep 17 14:50:27 CDT 2010
> Though, really, it's annoying that numpy.loadtxt needs both the
> readline function *and* the iterator protocol. If it just used
> iterators, you could do:
>
> def truncator(fh, delimiter='END'):
> for line in fh:
> if line.strip() == delimiter:
> break
> yield line
>
> numpy.loadtxt(truncator(c))
>
> Maybe I'll try to work up a patch for this.
That seemed easy... worth applying? Won't break compatibility, because
the previous loadtxt required both fname.readline and fname.__iter__,
while this requires only the latter.
Index: numpy/lib/npyio.py
===================================================================
--- numpy/lib/npyio.py (revision 8716)
+++ numpy/lib/npyio.py (working copy)
@@ -597,10 +597,11 @@
fh = bz2.BZ2File(fname)
else:
fh = open(fname, 'U')
- elif hasattr(fname, 'readline'):
- fh = fname
else:
- raise ValueError('fname must be a string or file handle')
+ try:
+ fh = iter(fname)
+ except:
+ raise ValueError('fname must be a string or file handle')
X = []
def flatten_dtype(dt):
@@ -633,14 +634,18 @@
# Skip the first `skiprows` lines
for i in xrange(skiprows):
- fh.readline()
+ try:
+ fh.next()
+ except StopIteration:
+ raise IOError('End-of-file reached before
encountering data.')
# Read until we find a line with some values, and use
# it to estimate the number of columns, N.
first_vals = None
while not first_vals:
- first_line = fh.readline()
- if not first_line: # EOF reached
+ try:
+ first_line = fh.next()
+ except StopIteration:
raise IOError('End-of-file reached before
encountering data.')
first_vals = split_line(first_line)
N = len(usecols or first_vals)
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