diff options
Diffstat (limited to 'numpy/lib/npyio.py')
| -rw-r--r-- | numpy/lib/npyio.py | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/numpy/lib/npyio.py b/numpy/lib/npyio.py index 9d539d6ac..2e68979c4 100644 --- a/numpy/lib/npyio.py +++ b/numpy/lib/npyio.py @@ -1204,7 +1204,8 @@ def genfromtxt(fname, dtype=float, comments='#', delimiter=None, usecols=None, names=None, excludelist=None, deletechars=None, replace_space='_', autostrip=False, case_sensitive=True, defaultfmt="f%i", - unpack=None, usemask=False, loose=True, invalid_raise=True): + unpack=None, usemask=False, loose=True, invalid_raise=True, + max_rows=None): """ Load data from a text file, with missing values handled as specified. @@ -1285,6 +1286,12 @@ def genfromtxt(fname, dtype=float, comments='#', delimiter=None, If True, an exception is raised if an inconsistency is detected in the number of columns. If False, a warning is emitted and the offending lines are skipped. + max_rows : int, optional + The maximum number of rows to read. Must not be used with skip_footer + at the same time. If given, the value must be at least 1. Default is + to read the entire file. + + .. versionadded:: 1.10.0 Returns ------- @@ -1353,6 +1360,14 @@ def genfromtxt(fname, dtype=float, comments='#', delimiter=None, dtype=[('intvar', '<i8'), ('fltvar', '<f8'), ('strvar', '|S5')]) """ + if max_rows is not None: + if skip_footer: + raise ValueError( + "The keywords 'skip_footer' and 'max_rows' can not be " + "specified at the same time.") + if max_rows < 1: + raise ValueError("'max_rows' must be at least 1.") + # Py3 data conversions to bytes, for convenience if comments is not None: comments = asbytes(comments) @@ -1647,8 +1662,8 @@ def genfromtxt(fname, dtype=float, comments='#', delimiter=None, # Skip an empty line if nbvalues == 0: continue - # Select only the columns we need if usecols: + # Select only the columns we need try: values = [values[_] for _ in usecols] except IndexError: @@ -1661,7 +1676,10 @@ def genfromtxt(fname, dtype=float, comments='#', delimiter=None, append_to_rows(tuple(values)) if usemask: append_to_masks(tuple([v.strip() in m - for (v, m) in zip(values, missing_values)])) + for (v, m) in zip(values, + missing_values)])) + if len(rows) == max_rows: + break if own_fhd: fhd.close() |