numpy.loadtxt(fname, dtype=, comments='#', delimiter=None, converters=None, skiprows=0, usecols=None, unpack=False, ndmin=0)
[source]
Load data from a text file.
Each row in the text file must have the same number of values.
Parameters: |
fname : file, str, or pathlib.Path File, filename, or generator to read. If the filename extension is dtype : data-type, optional Data-type of the resulting array; default: float. If this is a structured data-type, the resulting array will be 1-dimensional, and each row will be interpreted as an element of the array. In this case, the number of columns used must match the number of fields in the data-type. comments : str or sequence, optional The characters or list of characters used to indicate the start of a comment; default: ‘#’. delimiter : str, optional The string used to separate values. By default, this is any whitespace. converters : dict, optional A dictionary mapping column number to a function that will convert that column to a float. E.g., if column 0 is a date string: skiprows : int, optional Skip the first usecols : int or sequence, optional Which columns to read, with 0 being the first. For example, usecols = (1,4,5) will extract the 2nd, 5th and 6th columns. The default, None, results in all columns being read. New in version 1.11.0. Also when a single column has to be read it is possible to use an integer instead of a tuple. E.g unpack : bool, optional If True, the returned array is transposed, so that arguments may be unpacked using ndmin : int, optional The returned array will have at least New in version 1.6.0. |
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Returns: |
out : ndarray Data read from the text file. |
See also
genfromtxt
scipy.io.loadmat
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.
New in version 1.10.0.
The strings produced by the Python float.hex method can be used as input for floats.
>>> from io import StringIO # StringIO behaves like a file object >>> c = StringIO("0 1\n2 3") >>> np.loadtxt(c) array([[ 0., 1.], [ 2., 3.]])
>>> d = StringIO("M 21 72\nF 35 58") >>> np.loadtxt(d, dtype={'names': ('gender', 'age', 'weight'), ... 'formats': ('S1', 'i4', 'f4')}) array([('M', 21, 72.0), ('F', 35, 58.0)], dtype=[('gender', '|S1'), ('age', '<i4'), ('weight', '<f4')])
>>> c = StringIO("1,0,2\n3,0,4") >>> x, y = np.loadtxt(c, delimiter=',', usecols=(0, 2), unpack=True) >>> x array([ 1., 3.]) >>> y array([ 2., 4.])
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https://docs.scipy.org/doc/numpy-1.12.0/reference/generated/numpy.loadtxt.html