numpy.char.array#
- char.array(obj,itemsize=None,copy=True,unicode=None,order=None)[source]#
Create a
chararray
.Note
This class is provided for numarray backward-compatibility.New code (not concerned with numarray compatibility) should usearrays of type
bytes_
orstr_
and use the free functionsinnumpy.char
for fast vectorized string operations instead.Versus a NumPy array of dtype
bytes_
orstr_
, thisclass adds the following functionality:values automatically have whitespace removed from the endwhen indexed
comparison operators automatically remove whitespace from theend when comparing values
vectorized string operations are provided as methods(e.g.
chararray.endswith
)and infix operators (e.g.+,*,%
)
- Parameters:
- objarray of str or unicode-like
- itemsizeint, optional
itemsize is the number of characters per scalar in theresulting array. Ifitemsize is None, andobj is anobject array or a Python list, theitemsize will beautomatically determined. Ifitemsize is provided andobjis of type str or unicode, then theobj string will bechunked intoitemsize pieces.
- copybool, optional
If true (default), then the object is copied. Otherwise, a copywill only be made if
__array__
returns a copy, if obj is anested sequence, or if a copy is needed to satisfy any of the otherrequirements (itemsize, unicode,order, etc.).- unicodebool, optional
When true, the resulting
chararray
can contain Unicodecharacters, when false only 8-bit characters. If unicode isNone andobj is one of the following:then the unicode setting of the output array will beautomatically determined.
- order{‘C’, ‘F’, ‘A’}, optional
Specify the order of the array. If order is ‘C’ (default), then thearray will be in C-contiguous order (last-index varies thefastest). If order is ‘F’, then the returned arraywill be in Fortran-contiguous order (first-index varies thefastest). If order is ‘A’, then the returned array maybe in any order (either C-, Fortran-contiguous, or evendiscontiguous).
Examples
>>>importnumpyasnp>>>char_array=np.char.array(['hello','world','numpy','array'])>>>char_arraychararray(['hello', 'world', 'numpy', 'array'], dtype='<U5')