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NumPy Input and Output: fromfile() function

numpy.fromfile() function

The fromfile() function is used to construct an array from data in a text or binary file.

Syntax:

numpy.fromfile(file, dtype=float, count=-1, sep='')

Version: 1.15.0

Parameter:

Name Description Required /
Optional
file Open file object or filename.
file or str
Required
dtype Data type of the returned array. For binary files, it is used to determine the size and byte-order of the items in the file.
data-type
Required
count Number of items to read. -1 means all items (i.e., the complete file).
int
Required
sep Separator between items if file is a text file. Empty ("") separator means the file should be treated as binary.
Spaces (" ") in the separator match zero or more whitespace characters. A separator consisting only of spaces must match at least one whitespace.
str
Required

Notes:
Do not rely on the combination of tofile and fromfile for data storage, as the binary files generated are are not platform independent. In particular, no byte-order or data-type information is saved. Data can be stored in the platform independent .npy format using save and load instead.

NumPy.fromfile() method Example:

Construct an ndarray:

>>> import numpy as np
>>> dt = np.dtype([('time', [('min', int), ('sec', int)]),('temp', float)])
>>> x = np.zeros((1,), dtype=dt)
>>> x['time']['min'] = 15; x['temp'] = 95.25
>>> x

Output:

array([((15, 0), 95.25)],
      dtype=[('time', [('min', '<i4'), ('sec', '<i4')]), ('temp', '<f8')])

Python - NumPy Code Editor:

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