numpy.dtype

Ogni oggetto numpy.ndarray è accompagnato da un oggetto numpy.dtype (un’istanza della classe numpy.dtype) che fornisce informazioni sui suoi elementi

import numpy as np

x=np.array([1,2,3,4,5])
dt=x.dtype

Attributi

  1. dt.byteorder
  2. dt.itemsize
  3. dt.name
  4. dt.type
  5. …

Tipi

numpycharacter codelinguaggio Cvalori
np.int8‘b‘char-128
127
np.int16np.short‘h‘short-32 768
32 767
np.int32np.intc‘i‘int-2 147 483 648
2 147 483 647
np.int64np.int_‘l‘long-9 223 372 036 854 775 808
9 223 372 036 854 775 807
np.longlong‘q‘long long 
    
np.ubyte‘B‘unsigned char0
255
np.uint16np.ushort‘H‘unsigned short0
65 535
np.uint32np.uintc‘I‘unsigned int0
4 294 967 295
np.uint64np.uint‘L‘unsigned long0
18 446 744 073 709 551 615
np.longlong‘Q‘unsigned long long 
    
np.float16np.half‘e‘  
np.float32np.single‘f‘float 
np.float64np.double
np.float_
‘d‘double 
np.float128np.longdouble
np.longfloat
‘g‘long double 
    
np.complex64np.complex_
np.singlecomplex
np.csingle
‘F‘  
np.complex128np.complex_
np.cdouble
np.cfloat
‘D‘  
np.complex256np.longcomplex
np.clongdouble
np.clongfloat
‘G‘  
    
np.bool8np.bool_‘?‘  
……… 

numpy.dtype(…)

Restituisce un oggetto con le informazioni sul tipo di dato specificato

  • dtype(‘int32’)
  • dtype(‘int64’)
  • …