Reading unicode elements into numpy array

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逝去的感伤
逝去的感伤 2020-12-06 17:36

Consider a text file called \"new.txt\" containing the following elements:

μm
∂r
∆λ

In Python 2.7, I can read the file by typing:



        
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  •  悲哀的现实
    2020-12-06 18:03

    In memory, unicode strings are represented as UCS-2 or UCS-4, depending on how your Python interpreter was compiled. Your file is encoded in UTF-8, so you need to recode it before you can map it to the NumPy array. loadtxt() can't do the recoding for you -- after all NumPy is mainly targeted at numerical arrays.

    Assuming every line has the same number of characters, you could also use the more efficient variant

    s = codecs.open("new.txt", encoding="utf-8").read()
    arr = numpy.frombuffer(s, dtype="

    This will include the newline characters in the strings. To not include them, use

    arr = numpy.frombuffer(s.replace("\n", ""), dtype="

    Edit: If the lines of your file have different lengths and you would like to avoid the intermediate list, you can use

    arr = numpy.fromiter(codecs.open("new.txt", encoding="utf-8"), dtype="

    I'm not sure if this will internally create some temporary list, though.

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