Class PyArray

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable
    Direct Known Subclasses:
    PyArrayDerived

    public class PyArray
    extends PySequence
    implements java.lang.Cloneable
    A wrapper class around native java arrays. Instances of PyArray are created either by java functions or directly by the jarray module.

    See also the jarray module.

    See Also:
    Serialized Form
    • Field Detail

      • exposed_base

        public static final java.lang.Class exposed_base
    • Constructor Detail

      • PyArray

        public PyArray​(PyType type)
      • PyArray

        public PyArray​(PyArray toCopy)
      • PyArray

        public PyArray​(java.lang.Class type,
                       java.lang.Object data)
      • PyArray

        public PyArray​(java.lang.Class type,
                       int n)
    • Method Detail

      • zeros

        public static PyArray zeros​(int n,
                                    char typecode)
      • zeros

        public static PyArray zeros​(int n,
                                    java.lang.Class ctype)
      • array

        public static PyArray array​(PyObject init,
                                    java.lang.Class ctype)
        Create a PyArray storing ctype types and being initialised with initialiser.
        Parameters:
        init - an initialiser for the array - can be PyString or PySequence (including PyArray) or iterable type.
        ctype - Class type of the elements stored in the array.
        Returns:
        a new PyArray
      • __add__

        public PyObject __add__​(PyObject other)
        Adds (appends) two PyArrays together
        Overrides:
        __add__ in class PyObject
        Parameters:
        other - a PyArray to be added to the instance
        Returns:
        the result of the addition as a new PyArray instance
      • __findattr__

        public PyObject __findattr__​(java.lang.String name)
        Finds the attribute.
        Overrides:
        __findattr__ in class PyObject
        Parameters:
        name - the name of the attribute of interest
        Returns:
        the value for the attribute of the specified name
        See Also:
        PyObject.__findattr__(PyString)
      • __len__

        public int __len__()
        Length of the array
        Overrides:
        __len__ in class PyObject
        Returns:
        number of elements in the array
      • __repr__

        public PyString __repr__()
        String representation of PyArray
        Overrides:
        __repr__ in class PyObject
        Returns:
        string representation of PyArray
      • __tojava__

        public java.lang.Object __tojava__​(java.lang.Class c)
        Description copied from class: PyObject
        Equivalent to the Jython __tojava__ method. Tries to coerce this object to an instance of the requested Java class. Returns the special object Py.NoConversion if this PyObject can not be converted to the desired Java class.
        Overrides:
        __tojava__ in class PySequence
        Parameters:
        c - target Class for the conversion
        Returns:
        Java object converted to required class type if possible.
      • array_append

        public void array_append​(PyObject value)
      • append

        public void append​(PyObject value)
        Append new value x to the end of the array.
        Parameters:
        value - item to be appended to the array
      • array_byteswap

        public void array_byteswap()
      • byteswap

        public void byteswap()
        "Byteswap" all items of the array. This is only supported for values which are 1, 2, 4, or 8 bytes in size; for other types of values, RuntimeError is raised. It is useful when reading data from a file written on a machine with a different byte order.
      • clone

        public java.lang.Object clone()
        Implementation of Cloneable interface.
        Returns:
        copy of current PyArray
      • char2class

        public static java.lang.Class char2class​(char type)
                                          throws PyIgnoreMethodTag
        Converts a character code for the array type to a Java Class.

        The following character codes and their native types are supported:

        Type code native type
        z boolean
        c char
        b byte
        h short
        i int
        l long
        f float
        d double

        Parameters:
        type - character code for the array type
        Returns:
        Class of the native type
        Throws:
        PyIgnoreMethodTag
      • array_count

        public int array_count​(PyObject value)
      • count

        public PyInteger count​(PyObject value)
        Return the number of occurrences of x in the array.
        Parameters:
        value - instances of the value to be counted
        Returns:
        number of time value was found in the array.
      • array_extend

        public void array_extend​(PyObject iterable)
      • extend

        public void extend​(PyObject iterable)
        Append items from iterable to the end of the array. If iterable is another array, it must have exactly the same type code; if not, TypeError will be raised. If iterable is not an array, it must be iterable and its elements must be the right type to be appended to the array. Changed in version 2.4: Formerly, the argument could only be another array.
        Parameters:
        iterable - iterable object used to extend the array
      • fromfile

        public void fromfile​(PyObject f,
                             int count)
        Read count items (as machine values) from the file object f and append them to the end of the array. If less than count items are available, EOFError is raised, but the items that were available are still inserted into the array. f must be a real built-in file object; something else with a read() method won't do.
        Parameters:
        f - Python builtin file object to retrieve data
        count - number of array elements to read
      • array_fromlist

        public void array_fromlist​(PyObject obj)
      • fromlist

        public void fromlist​(PyObject obj)
        Append items from the list. This is equivalent to "for x in list: a.append(x)"except that if there is a type error, the array is unchanged.
        Parameters:
        obj - input list object that will be appended to the array
      • fromstring

        public void fromstring​(java.lang.String input)
        Appends items from the string, interpreting the string as an array of machine values (as if it had been read from a file using the fromfile() method).
        Parameters:
        input - string of bytes containing array data
      • getArray

        public java.lang.Object getArray()
                                  throws PyIgnoreMethodTag
        Return the internal Java array storage of the PyArray instance
        Returns:
        the Array store.
        Throws:
        PyIgnoreMethodTag
      • getItemsize

        public int getItemsize()
        Getter for the storage size of the array's type.

        The sizes returned by this method represent the number of bytes used to store the type. In the case of streams, this is the number of bytes written to, or read from a stream. For memory this value is the minimum number of bytes required to store the type.

        This method is used by other methods to define read/write quanta from strings and streams.

        Values returned are:

        Type Size
        boolean 1
        byte 1
        char 1
        short 2
        int 4
        long 8
        float 4
        double 8
        Returns:
        number of bytes used to store array type.
      • getTypecode

        public java.lang.String getTypecode()
                                     throws PyIgnoreMethodTag
        Getter for the type code of the array. char2class describes the possible type codes and their meaning.
        Returns:
        single character type code for the array
        Throws:
        PyIgnoreMethodTag
      • array_index

        public int array_index​(PyObject value)
      • index

        public PyObject index​(PyObject value)
        Return the smallest i such that i is the index of the first occurrence of value in the array.
        Parameters:
        value - value to find the index of
        Returns:
        index of the first occurance of value
      • array_insert

        public void array_insert​(int index,
                                 PyObject value)
      • insert

        public void insert​(int index,
                           PyObject value)
        Insert a new item with value value in the array before position index. Negative values are treated as being relative to the end of the array.
        Parameters:
        index - insert position
        value - value to be inserted into array
      • array_pop

        public PyObject array_pop()
      • array_pop

        public PyObject array_pop​(int i)
      • pop

        public PyObject pop()
        Removes the item with the index index from the array and returns it. The optional argument defaults to -1, so that by default the last item is removed and returned.
      • pop

        public PyObject pop​(int index)
        Removes the item with the index index from the array and returns it. The optional argument defaults to -1, so that by default the last item is removed and returned.
        Parameters:
        index - array location to be popped from the array
        Returns:
        array element popped from index
      • array_remove

        public void array_remove​(PyObject value)
      • remove

        public void remove​(PyObject value)
        Remove the first occurrence of value from the array.
        Parameters:
        value - array value to be removed
      • array_reverse

        public void array_reverse()
      • reverse

        public void reverse()
        Reverse the elements in the array
      • array_tofile

        public void array_tofile​(PyObject f)
      • array_write

        public void array_write​(PyObject f)
      • tofile

        public void tofile​(PyObject f)
        Write all items (as machine values) to the file object f.
        Parameters:
        f - Python builtin file object to write data
      • array_tolist

        public PyObject array_tolist()
      • tolist

        public PyObject tolist()
        Convert the array to an ordinary list with the same items.
        Returns:
        array contents as a list
      • array_tostring

        public PyObject array_tostring()
      • tostring

        public java.lang.String tostring()
        Convert the array to an array of machine values and return the string representation (the same sequence of bytes that would be written to a file by the tofile() method.)