Lib/test/test_fileinput.py

   1 '''
   2 Tests for fileinput module.
   3 Nick Mathewson
   4 '''
   5
   6 import unittest
   7 from test.test_support import verbose, TESTFN, run_unittest
   8 from test.test_support import unlink as safe_unlink
   9 import sys, re
  10 from StringIO import StringIO
  11 from fileinput import FileInput, hook_encoded
  12
  13 # The fileinput module has 2 interfaces: the FileInput class which does
  14 # all the work, and a few functions (input, etc.) that use a global _state
  15 # variable.  We only test the FileInput class, since the other functions
  16 # only provide a thin facade over FileInput.
  17
  18 # Write lines (a list of lines) to temp file number i, and return the
  19 # temp file's name.
  20 def writeTmp(i, lines, mode='w'):  # opening in text mode is the default
  21     name = TESTFN + str(i)
  22     f = open(name, mode)
  23     f.writelines(lines)
  24     f.close()
  25     return name
  26
  27 def remove_tempfiles(*names):
  28     for name in names:
  29         safe_unlink(name)
  30
  31 class BufferSizesTests(unittest.TestCase):
  32     def test_buffer_sizes(self):
  33         # First, run the tests with default and teeny buffer size.
  34         for round, bs in (0, 0), (1, 30):
  35             try:
  36                 t1 = writeTmp(1, ["Line %s of file 1\n" % (i+1) for i in range(15)])
  37                 t2 = writeTmp(2, ["Line %s of file 2\n" % (i+1) for i in range(10)])
  38                 t3 = writeTmp(3, ["Line %s of file 3\n" % (i+1) for i in range(5)])
  39                 t4 = writeTmp(4, ["Line %s of file 4\n" % (i+1) for i in range(1)])
  40                 self.buffer_size_test(t1, t2, t3, t4, bs, round)
  41             finally:
  42                 remove_tempfiles(t1, t2, t3, t4)
  43
  44     def buffer_size_test(self, t1, t2, t3, t4, bs=0, round=0):
  45         pat = re.compile(r'LINE (\d+) OF FILE (\d+)')
  46
  47         start = 1 + round*6
  48         if verbose:
  49             print '%s. Simple iteration (bs=%s)' % (start+0, bs)
  50         fi = FileInput(files=(t1, t2, t3, t4), bufsize=bs)
  51         lines = list(fi)
  52         fi.close()
  53         self.assertEqual(len(lines), 31)
  54         self.assertEqual(lines[4], 'Line 5 of file 1\n')
  55         self.assertEqual(lines[30], 'Line 1 of file 4\n')
  56         self.assertEqual(fi.lineno(), 31)
  57         self.assertEqual(fi.filename(), t4)
  58
  59         if verbose:
  60             print '%s. Status variables (bs=%s)' % (start+1, bs)
  61         fi = FileInput(files=(t1, t2, t3, t4), bufsize=bs)
  62         s = "x"
  63         while s and s != 'Line 6 of file 2\n':
  64             s = fi.readline()
  65         self.assertEqual(fi.filename(), t2)
  66         self.assertEqual(fi.lineno(), 21)
  67         self.assertEqual(fi.filelineno(), 6)
  68         self.assertFalse(fi.isfirstline())
  69         self.assertFalse(fi.isstdin())
  70
  71         if verbose:
  72             print '%s. Nextfile (bs=%s)' % (start+2, bs)
  73         fi.nextfile()
  74         self.assertEqual(fi.readline(), 'Line 1 of file 3\n')
  75         self.assertEqual(fi.lineno(), 22)
  76         fi.close()
  77
  78         if verbose:
  79             print '%s. Stdin (bs=%s)' % (start+3, bs)
  80         fi = FileInput(files=(t1, t2, t3, t4, '-'), bufsize=bs)
  81         savestdin = sys.stdin
  82         try:
  83             sys.stdin = StringIO("Line 1 of stdin\nLine 2 of stdin\n")
  84             lines = list(fi)
  85             self.assertEqual(len(lines), 33)
  86             self.assertEqual(lines[32], 'Line 2 of stdin\n')
  87             self.assertEqual(fi.filename(), '<stdin>')
  88             fi.nextfile()
  89         finally:
  90             sys.stdin = savestdin
  91
  92         if verbose:
  93             print '%s. Boundary conditions (bs=%s)' % (start+4, bs)
  94         fi = FileInput(files=(t1, t2, t3, t4), bufsize=bs)
  95         self.assertEqual(fi.lineno(), 0)
  96         self.assertEqual(fi.filename(), None)
  97         fi.nextfile()
  98         self.assertEqual(fi.lineno(), 0)
  99         self.assertEqual(fi.filename(), None)
 100
 101         if verbose:
 102             print '%s. Inplace (bs=%s)' % (start+5, bs)
 103         savestdout = sys.stdout
 104         try:
 105             fi = FileInput(files=(t1, t2, t3, t4), inplace=1, bufsize=bs)
 106             for line in fi:
 107                 line = line[:-1].upper()
 108                 print line
 109             fi.close()
 110         finally:
 111             sys.stdout = savestdout
 112
 113         fi = FileInput(files=(t1, t2, t3, t4), bufsize=bs)
 114         for line in fi:
 115             self.assertEqual(line[-1], '\n')
 116             m = pat.match(line[:-1])
 117             self.assertNotEqual(m, None)
 118             self.assertEqual(int(m.group(1)), fi.filelineno())
 119         fi.close()
 120
 121 class FileInputTests(unittest.TestCase):
 122     def test_zero_byte_files(self):
 123         try:
 124             t1 = writeTmp(1, [""])
 125             t2 = writeTmp(2, [""])
 126             t3 = writeTmp(3, ["The only line there is.\n"])
 127             t4 = writeTmp(4, [""])
 128             fi = FileInput(files=(t1, t2, t3, t4))
 129
 130             line = fi.readline()
 131             self.assertEqual(line, 'The only line there is.\n')
 132             self.assertEqual(fi.lineno(), 1)
 133             self.assertEqual(fi.filelineno(), 1)
 134             self.assertEqual(fi.filename(), t3)
 135
 136             line = fi.readline()
 137             self.assertFalse(line)
 138             self.assertEqual(fi.lineno(), 1)
 139             self.assertEqual(fi.filelineno(), 0)
 140             self.assertEqual(fi.filename(), t4)
 141             fi.close()
 142         finally:
 143             remove_tempfiles(t1, t2, t3, t4)
 144
 145     def test_files_that_dont_end_with_newline(self):
 146         try:
 147             t1 = writeTmp(1, ["A\nB\nC"])
 148             t2 = writeTmp(2, ["D\nE\nF"])
 149             fi = FileInput(files=(t1, t2))
 150             lines = list(fi)
 151             self.assertEqual(lines, ["A\n", "B\n", "C", "D\n", "E\n", "F"])
 152             self.assertEqual(fi.filelineno(), 3)
 153             self.assertEqual(fi.lineno(), 6)
 154         finally:
 155             remove_tempfiles(t1, t2)
 156
 157     def test_unicode_filenames(self):
 158         try:
 159             t1 = writeTmp(1, ["A\nB"])
 160             encoding = sys.getfilesystemencoding()
 161             if encoding is None:
 162                 encoding = 'ascii'
 163             fi = FileInput(files=unicode(t1, encoding))
 164             lines = list(fi)
 165             self.assertEqual(lines, ["A\n", "B"])
 166         finally:
 167             remove_tempfiles(t1)
 168
 169     def test_fileno(self):
 170         try:
 171             t1 = writeTmp(1, ["A\nB"])
 172             t2 = writeTmp(2, ["C\nD"])
 173             fi = FileInput(files=(t1, t2))
 174             self.assertEqual(fi.fileno(), -1)
 175             line = fi.next()
 176             self.assertNotEqual(fi.fileno(), -1)
 177             fi.nextfile()
 178             self.assertEqual(fi.fileno(), -1)
 179             line = list(fi)
 180             self.assertEqual(fi.fileno(), -1)
 181         finally:
 182             remove_tempfiles(t1, t2)
 183
 184     def test_opening_mode(self):
 185         try:
 186             # invalid mode, should raise ValueError
 187             fi = FileInput(mode="w")
 188             self.fail("FileInput should reject invalid mode argument")
 189         except ValueError:
 190             pass
 191         try:
 192             # try opening in universal newline mode
 193             t1 = writeTmp(1, ["A\nB\r\nC\rD"], mode="wb")
 194             fi = FileInput(files=t1, mode="U")
 195             lines = list(fi)
 196             self.assertEqual(lines, ["A\n", "B\n", "C\n", "D"])
 197         finally:
 198             remove_tempfiles(t1)
 199
 200     def test_file_opening_hook(self):
 201         try:
 202             # cannot use openhook and inplace mode
 203             fi = FileInput(inplace=1, openhook=lambda f,m: None)
 204             self.fail("FileInput should raise if both inplace "
 205                              "and openhook arguments are given")
 206         except ValueError:
 207             pass
 208         try:
 209             fi = FileInput(openhook=1)
 210             self.fail("FileInput should check openhook for being callable")
 211         except ValueError:
 212             pass
 213         try:
 214             t1 = writeTmp(1, ["A\nB"], mode="wb")
 215             fi = FileInput(files=t1, openhook=hook_encoded("rot13"))
 216             lines = list(fi)
 217             self.assertEqual(lines, ["N\n", "O"])
 218         finally:
 219             remove_tempfiles(t1)
 220
 221 def test_main():
 222     run_unittest(BufferSizesTests, FileInputTests)
 223
 224 if __name__ == "__main__":
 225     test_main()