numpy.array2string
- numpy. array2string ( a, max_line_width=None, precision=None, suppress_small=None, separator=' ', prefix='', style=<no value>, formatter=None, threshold=None, edgeitems=None, sign=None, floatmode=None, suffix='', *, legacy=None ) [source]
-
Return a string representation of an array.
- Parameters
-
- a ndarray
-
Input array.
- max_line_width int, optional
-
Inserts newlines if text is longer than
max_line_width
. Defaults tonumpy.get_printoptions()['linewidth']
. - precision int or None, optional
-
Floating point precision. Defaults to
numpy.get_printoptions()['precision']
. - suppress_small bool, optional
-
Represent numbers “very close” to zero as zero; default is False. Very close is defined by precision: if the precision is 8, e.g., numbers smaller (in absolute value) than 5e-9 are represented as zero. Defaults to
numpy.get_printoptions()['suppress']
. - separator str, optional
-
Inserted between elements.
- prefix str, optional
- suffix str, optional
-
The length of the prefix and suffix strings are used to respectively align and wrap the output. An array is typically printed as:
prefix + array2string(a) + suffix
The output is left-padded by the length of the prefix string, and wrapping is forced at the column
max_line_width - len(suffix)
. It should be noted that the content of prefix and suffix strings are not included in the output. - style _NoValue, optional
-
Has no effect, do not use.
Deprecated since version 1.14.0.
- formatter dict of callables, optional
-
If not None, the keys should indicate the type(s) that the respective formatting function applies to. Callables should return a string. Types that are not specified (by their corresponding keys) are handled by the default formatters. Individual types for which a formatter can be set are:
- ‘bool’
- ‘int’
- ‘timedelta’ : a
numpy.timedelta64
- ‘datetime’ : a
numpy.datetime64
- ‘float’
- ‘longfloat’ : 128-bit floats
- ‘complexfloat’
- ‘longcomplexfloat’ : composed of two 128-bit floats
- ‘void’ : type
numpy.void
- ‘numpystr’ : types
numpy.string_
andnumpy.unicode_
Other keys that can be used to set a group of types at once are:
- ‘all’ : sets all types
- ‘int_kind’ : sets ‘int’
- ‘float_kind’ : sets ‘float’ and ‘longfloat’
- ‘complex_kind’ : sets ‘complexfloat’ and ‘longcomplexfloat’
- ‘str_kind’ : sets ‘numpystr’
- threshold int, optional
-
Total number of array elements which trigger summarization rather than full repr. Defaults to
numpy.get_printoptions()['threshold']
. - edgeitems int, optional
-
Number of array items in summary at beginning and end of each dimension. Defaults to
numpy.get_printoptions()['edgeitems']
. - sign string, either ‘-’, ‘+’, or ‘ ‘, optional
-
Controls printing of the sign of floating-point types. If ‘+’, always print the sign of positive values. If ‘ ‘, always prints a space (whitespace character) in the sign position of positive values. If ‘-’, omit the sign character of positive values. Defaults to
numpy.get_printoptions()['sign']
. - floatmode str, optional
-
Controls the interpretation of the
precision
option for floating-point types. Defaults tonumpy.get_printoptions()['floatmode']
. Can take the following values:- ‘fixed’: Always print exactly
precision
fractional digits, even if this would print more or fewer digits than necessary to specify the value uniquely. - ‘unique’: Print the minimum number of fractional digits necessary to represent each value uniquely. Different elements may have a different number of digits. The value of the
precision
option is ignored. - ‘maxprec’: Print at most
precision
fractional digits, but if an element can be uniquely represented with fewer digits only print it with that many. - ‘maxprec_equal’: Print at most
precision
fractional digits, but if every element in the array can be uniquely represented with an equal number of fewer digits, use that many digits for all elements.
- ‘fixed’: Always print exactly
-
legacy
string or
False
, optional -
If set to the string
‘1.13’
enables 1.13 legacy printing mode. This approximates numpy 1.13 print output by including a space in the sign position of floats and different behavior for 0d arrays. If set toFalse
, disables legacy mode. Unrecognized strings will be ignored with a warning for forward compatibility.New in version 1.14.0.
- Returns
-
- array_str str
-
String representation of the array.
- Raises
-
- TypeError
-
if a callable in
formatter
does not return a string.
See also
Notes
If a formatter is specified for a certain type, the
precision
keyword is ignored for that type.This is a very flexible function;
array_repr
andarray_str
are usingarray2string
internally so keywords with the same name should work identically in all three functions.Examples
>>> x = np.array([1e-16,1,2,3]) >>> np.array2string(x, precision=2, separator=',', ... suppress_small=True) '[0.,1.,2.,3.]'
>>> x = np.arange(3.) >>> np.array2string(x, formatter={'float_kind':lambda x: "%.2f" % x}) '[0.00 1.00 2.00]'
>>> x = np.arange(3) >>> np.array2string(x, formatter={'int':lambda x: hex(x)}) '[0x0 0x1 0x2]'
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Licensed under the 3-clause BSD License.
https://numpy.org/doc/1.22/reference/generated/numpy.array2string.html