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# numpy.array2string

`numpy.``array2string`(a, max_line_width=None, precision=None, suppress_small=None, separator=' ', prefix='', style=<built-in function repr>, formatter=None)

  Return a string representation of an array.

  > Parameters: | a : ndarray Input array. max_line_width : int, optional The maximum number of columns the string should span. Newline characters splits the string appropriately after array elements. precision : int, optional Floating point precision. Default is the current printing precision (usually 8), which can be altered using `set_printoptions`. suppress_small : bool, optional Represent very small numbers as zero. A number is “very small” if it is smaller than the current printing precision. separator : str, optional Inserted between elements. prefix : str, optional An array is typically printed as:
  >     'prefix(' + array2string(a) + ')'
  > The length of the prefix string is used to align the output correctly. style : function, optional A function that accepts an ndarray and returns a string. Used only when the shape of a is equal to `()`, i.e. for 0-D arrays. 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
  >     - 'numpy_str' : types `numpy.string_` and `numpy.unicode_`
  >     - 'str' : all other strings
  > 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 'str' and 'numpystr'
  Returns: | array_str : str String representation of the array.
  Raises: | TypeError if a callable in `formatter` does not return a string.

  See also

  `array_str`, `array_repr`, `set_printoptions`, `get_printoptions`

  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` and `array_str` are using `array2string` internally so keywords with the same name should work identically in all three functions.

  Examples

      >>> x = np.array([1e-16,1,2,3])
      >>> print 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)})
      '[0x0L 0x1L 0x2L]'