bpo-40286: Use random.randbytes() in tests

Lib/test/test_bz2.py

@@ -710,7 +710,7 @@ def testEOFError(self):
     def testDecompress4G(self, size):
         # "Test BZ2Decompressor.decompress() with >4GiB input"
         blocksize = 10 * 1024 * 1024
-        block = random.getrandbits(blocksize * 8).to_bytes(blocksize, 'little')
+        block = random.randbytes(blocksize)
         try:
             data = block * (size // blocksize + 1)
             compressed = bz2.compress(data)

Lib/test/test_lzma.py

@@ -350,7 +350,7 @@ def test_compressor_bigmem(self, size):
     def test_decompressor_bigmem(self, size):
         lzd = LZMADecompressor()
         blocksize = 10 * 1024 * 1024
-        block = random.getrandbits(blocksize * 8).to_bytes(blocksize, "little")
+        block = random.randbytes(blocksize)
         try:
             input = block * (size // blocksize + 1)
             cdata = lzma.compress(input)

Lib/test/test_tarfile.py

@@ -386,7 +386,7 @@ def test_null_tarfile(self):
     def test_ignore_zeros(self):
         # Test TarFile's ignore_zeros option.
         # generate 512 pseudorandom bytes
-        data = Random(0).getrandbits(512*8).to_bytes(512, 'big')
+        data = Random(0).randbytes(512)
         for char in (b'\0', b'a'):
             # Test if EOFHeaderError ('\0') and InvalidHeaderError ('a')
             # are ignored correctly.

Lib/test/test_zipfile.py

@@ -16,7 +16,7 @@
 
 
 from tempfile import TemporaryFile
-from random import randint, random, getrandbits
+from random import randint, random, randbytes
 
 from test.support import script_helper
 from test.support import (TESTFN, findfile, unlink, rmtree, temp_dir, temp_cwd,
@@ -33,9 +33,6 @@
                    ('ziptest2dir/ziptest3dir/_ziptest3', 'azsxdcfvgb'),
                    ('ziptest2dir/ziptest3dir/ziptest4dir/_ziptest3', '6y7u8i9o0p')]
 
-def getrandbytes(size):
-    return getrandbits(8 * size).to_bytes(size, 'little')
-
 def get_files(test):
     yield TESTFN2
     with TemporaryFile() as f:
@@ -324,7 +321,7 @@ def test_read_return_size(self):
         # than requested.
         for test_size in (1, 4095, 4096, 4097, 16384):
             file_size = test_size + 1
-            junk = getrandbytes(file_size)
+            junk = randbytes(file_size)
             with zipfile.ZipFile(io.BytesIO(), "w", self.compression) as zipf:
                 zipf.writestr('foo', junk)
                 with zipf.open('foo', 'r') as fp:
@@ -2423,8 +2420,8 @@ def test_open_write(self):
 class TestsWithMultipleOpens(unittest.TestCase):
     @classmethod
     def setUpClass(cls):
-        cls.data1 = b'111' + getrandbytes(10000)
-        cls.data2 = b'222' + getrandbytes(10000)
+        cls.data1 = b'111' + randbytes(10000)
+        cls.data2 = b'222' + randbytes(10000)
 
     def make_test_archive(self, f):
         # Create the ZIP archive

Lib/test/test_zlib.py

@@ -134,8 +134,7 @@ def check_big_compress_buffer(self, size, compress_func):
         # Generate 10 MiB worth of random, and expand it by repeating it.
         # The assumption is that zlib's memory is not big enough to exploit
         # such spread out redundancy.
-        data = b''.join([random.getrandbits(8 * _1M).to_bytes(_1M, 'little')
-                        for i in range(10)])
+        data = random.randbytes(_1M * 10)
         data = data * (size // len(data) + 1)
         try:
             compress_func(data)