# Tests StringIO and cStringIO
import unittest
import StringIO
import cStringIO
import types
import array
import sys
from test import test_support
class TestGenericStringIO(unittest.TestCase):
# use a class variable MODULE to define which module is being tested
# Line of data to test as string
_line = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!'
# Constructor to use for the test data (._line is passed to this
# constructor)
constructor = str
def setUp(self):
self._lines = self.constructor((self._line + '\n') * 5)
self._fp = self.MODULE.StringIO(self._lines)
def test_reads(self):
eq = self.assertEqual
self.assertRaises(TypeError, self._fp.seek)
eq(self._fp.read(10), self._line[:10])
eq(self._fp.read(0), '')
eq(self._fp.readline(0), '')
eq(self._fp.readline(), self._line[10:] + '\n')
eq(len(self._fp.readlines(60)), 2)
self._fp.seek(0)
eq(self._fp.readline(-1), self._line + '\n')
def test_writes(self):
f = self.MODULE.StringIO()
self.assertRaises(TypeError, f.seek)
f.write(self._line[:6])
f.seek(3)
f.write(self._line[20:26])
f.write(self._line[52])
self.assertEqual(f.getvalue(), 'abcuvwxyz!')
def test_writelines(self):
f = self.MODULE.StringIO()
f.writelines([self._line[0], self._line[1], self._line[2]])
f.seek(0)
self.assertEqual(f.getvalue(), 'abc')
def test_writelines_error(self):
def errorGen():
yield 'a'
raise KeyboardInterrupt()
f = self.MODULE.StringIO()
self.assertRaises(KeyboardInterrupt, f.writelines, errorGen())
def test_truncate(self):
eq = self.assertEqual
f = self.MODULE.StringIO()
f.write(self._lines)
f.seek(10)
f.truncate()
eq(f.getvalue(), 'abcdefghij')
f.truncate(5)
eq(f.getvalue(), 'abcde')
f.write('xyz')
eq(f.getvalue(), 'abcdexyz')
self.assertRaises(IOError, f.truncate, -1)
f.close()
self.assertRaises(ValueError, f.write, 'frobnitz')
def test_closed_flag(self):
f = self.MODULE.StringIO()
self.assertEqual(f.closed, False)
f.close()
self.assertEqual(f.closed, True)
f = self.MODULE.StringIO("abc")
self.assertEqual(f.closed, False)
f.close()
self.assertEqual(f.closed, True)
def test_isatty(self):
f = self.MODULE.StringIO()
self.assertRaises(TypeError, f.isatty, None)
self.assertEqual(f.isatty(), False)
f.close()
self.assertRaises(ValueError, f.isatty)
def test_iterator(self):
eq = self.assertEqual
unless = self.assertTrue
eq(iter(self._fp), self._fp)
# Does this object support the iteration protocol?
unless(hasattr(self._fp, '__iter__'))
unless(hasattr(self._fp, 'next'))
i = 0
for line in self._fp:
eq(line, self._line + '\n')
i += 1
eq(i, 5)
self._fp.close()
self.assertRaises(ValueError, self._fp.next)
def test_getvalue(self):
self._fp.close()
self.assertRaises(ValueError, self._fp.getvalue)
@test_support.bigmemtest(test_support._2G + 2**26, memuse=2.001)
def test_reads_from_large_stream(self, size):
linesize = 2**26 # 64 MiB
lines = ['x' * (linesize - 1) + '\n'] * (size // linesize) + \
['y' * (size % linesize)]
f = self.MODULE.StringIO(''.join(lines))
for i, expected in enumerate(lines):
line = f.read(len(expected))
self.assertEqual(len(line), len(expected))
self.assertEqual(line, expected)
self.assertEqual(f.read(), '')
f.seek(0)
for i, expected in enumerate(lines):
line = f.readline()
self.assertEqual(len(line), len(expected))
self.assertEqual(line, expected)
self.assertEqual(f.readline(), '')
f.seek(0)
self.assertEqual(f.readlines(), lines)
self.assertEqual(f.readlines(), [])
f.seek(0)
self.assertEqual(f.readlines(size), lines)
self.assertEqual(f.readlines(), [])
# In worst case cStringIO requires 2 + 1 + 1/2 + 1/2**2 + ... = 4
# bytes per input character.
@test_support.bigmemtest(test_support._2G, memuse=4)
def test_writes_to_large_stream(self, size):
s = 'x' * 2**26 # 64 MiB
f = self.MODULE.StringIO()
n = size
while n > len(s):
f.write(s)
n -= len(s)
s = None
f.write('x' * n)
self.assertEqual(len(f.getvalue()), size)
class TestStringIO(TestGenericStringIO):
MODULE = StringIO
def test_unicode(self):
if not test_support.have_unicode: return
# The StringIO module also supports concatenating Unicode
# snippets to larger Unicode strings. This is tested by this
# method. Note that cStringIO does not support this extension.
f = self.MODULE.StringIO()
f.write(self._line[:6])
f.seek(3)
f.write(unicode(self._line[20:26]))
f.write(unicode(self._line[52]))
s = f.getvalue()
self.assertEqual(s, unicode('abcuvwxyz!'))
self.assertEqual(type(s), types.UnicodeType)
class TestcStringIO(TestGenericStringIO):
MODULE = cStringIO
def test_array_support(self):
# Issue #1730114: cStringIO should accept array objects
a = array.array('B', [0,1,2])
f = self.MODULE.StringIO(a)
self.assertEqual(f.getvalue(), '\x00\x01\x02')
def test_unicode(self):
if not test_support.have_unicode: return
# The cStringIO module converts Unicode strings to character
# strings when writing them to cStringIO objects.
# Check that this works.
f = self.MODULE.StringIO()
f.write(u'abcde')
s = f.getvalue()
self.assertEqual(s, 'abcde')
self.assertEqual(type(s), str)
f = self.MODULE.StringIO(u'abcde')
s = f.getvalue()
self.assertEqual(s, 'abcde')
self.assertEqual(type(s), str)
self.assertRaises(UnicodeEncodeError, self.MODULE.StringIO, u'\xf4')
import sys
if sys.platform.startswith('java'):
# Jython doesn't have a buffer object, so we just do a useless
# fake of the buffer tests.
buffer = str
class TestBufferStringIO(TestStringIO):
constructor = buffer
class TestBuffercStringIO(TestcStringIO):
constructor = buffer
class TestMemoryviewcStringIO(TestcStringIO):
constructor = memoryview
def test_main():
test_support.run_unittest(TestStringIO, TestcStringIO)
with test_support.check_py3k_warnings(("buffer.. not supported",
DeprecationWarning)):
test_support.run_unittest(TestBufferStringIO, TestBuffercStringIO)
test_support.run_unittest(TestMemoryviewcStringIO)
if __name__ == '__main__':
test_main()