Demonstration script for Jython bug with array module.

jython_array_bugs.py

import sys
import array

def test_signed(typecode):
    try:
        a = array.array(typecode)

        # Create byte representation of exactly one item
        byte_item = bytes()
        for i in range(a.itemsize):
            # Add a byte
            byte_item += str(i).encode()

        try:
            a.frombytes(byte_item)
        except AttributeError:
            # Python 2 uses fromstring
            a.fromstring(byte_item)

        if len(a) != 1:
            print("Test %s: itemsize does not match grouping" % typecode)
            return

        # Byteswapping twice should be the same as not byteswapping at all, test that
        a.byteswap()
        list_a = a.tolist()
        a.byteswap()
        a.byteswap()
        list_b = a.tolist()
    except:
        exc_type, exc_value, exc_traceback = sys.exc_info()
        print("Test %s: error %r" % (typecode, exc_value))
        return


    if list_a != list_b:
        print("Test %c: byteswapping twice returned different results" % typecode)
        return

    print("Test %s: passed" % typecode)

def test_unsigned(typecode):

    try:
        a = array.array(typecode)

        # Create byte representation of exactly one item
        byte_item = bytes()
        for i in range(a.itemsize):
            # Add a byte
            byte_item += str(i).encode()

        try:
            a.frombytes(byte_item)
        except AttributeError:
            # Python 2 uses fromstring
            a.fromstring(byte_item)

        if len(a) != 1:
            print("Test %s: itemsize does not match grouping" % typecode)
            return

        # Byteswapping twice should be the same as not byteswapping at all, test that
        a.byteswap()
        list_a = a.tolist()
        a.byteswap()
        a.byteswap()
        list_b = a.tolist()
    except:
        exc_type, exc_value, exc_traceback = sys.exc_info()
        print("Test %s: error %r" % (typecode, exc_value))
        return

    if list_a != list_b:
        print("Test %s: byteswapping twice returned different results" % typecode)
        return

    # Make sure all are positive
    for item in list_a:
        if item < 0:
            print("Test %s: unsigned type returned negative byteswap value" % typecode)
            return

    print("Test %s: passed" % typecode)

def test_string(typecode):
    # c is char type, u is unicode type
    if typecode == "u":
        literal = u"hello"
    else:
        literal = "hello"

    try:
        a = array.array(typecode)
        a.fromlist(list(literal))

        # Byteswapping twice should be the same as not byteswapping at all, test that
        a.byteswap()
        list_a = a.tolist()
        a.byteswap()
        a.byteswap()
        list_b = a.tolist()
    except:
        exc_type, exc_value, exc_traceback = sys.exc_info()
        print("Test %s: error %r" % (typecode, exc_value))
        return

    if list_a != list_b:
        print("Test %s: byteswapping twice returned different results" % typecode)
        return

    print("Test %s: passed" % typecode)

# Try all typecodes
typecodes = []
for c in range(256):
    c = chr(c)
    try:
        a = array.array(c)
    except ValueError:
        pass
    else:
        typecodes.append(c)

typecodes = "".join(sorted(typecodes))

print("Typecodes: %s" % typecodes)

for typecode in typecodes:
    if typecode == "u" or typecode == "c":
        test_string(typecode)
    elif typecode.isupper():
        test_unsigned(typecode)
    else:
        test_signed(typecode)