Patch #1215184: FileInput now can be given an opening hook which can
be used to control how files are opened.
diff --git a/Lib/fileinput.py b/Lib/fileinput.py
index 004cf09..2c4c9dc 100644
--- a/Lib/fileinput.py
+++ b/Lib/fileinput.py
@@ -88,8 +88,9 @@
DEFAULT_BUFSIZE = 8*1024
-def input(files=None, inplace=0, backup="", bufsize=0, mode="r"):
- """input([files[, inplace[, backup[, mode]]]])
+def input(files=None, inplace=0, backup="", bufsize=0,
+ mode="r", openhook=None):
+ """input([files[, inplace[, backup[, mode[, openhook]]]]])
Create an instance of the FileInput class. The instance will be used
as global state for the functions of this module, and is also returned
@@ -99,7 +100,7 @@
global _state
if _state and _state._file:
raise RuntimeError, "input() already active"
- _state = FileInput(files, inplace, backup, bufsize, mode)
+ _state = FileInput(files, inplace, backup, bufsize, mode, openhook)
return _state
def close():
@@ -181,7 +182,7 @@
return _state.isstdin()
class FileInput:
- """class FileInput([files[, inplace[, backup[, mode]]]])
+ """class FileInput([files[, inplace[, backup[, mode[, openhook]]]]])
Class FileInput is the implementation of the module; its methods
filename(), lineno(), fileline(), isfirstline(), isstdin(), fileno(),
@@ -193,7 +194,8 @@
sequential order; random access and readline() cannot be mixed.
"""
- def __init__(self, files=None, inplace=0, backup="", bufsize=0, mode="r"):
+ def __init__(self, files=None, inplace=0, backup="", bufsize=0,
+ mode="r", openhook=None):
if isinstance(files, basestring):
files = (files,)
else:
@@ -222,6 +224,11 @@
raise ValueError("FileInput opening mode must be one of "
"'r', 'rU', 'U' and 'rb'")
self._mode = mode
+ if inplace and openhook:
+ raise ValueError("FileInput cannot use an opening hook in inplace mode")
+ elif openhook and not callable(openhook):
+ raise ValueError("FileInput openhook must be callable")
+ self._openhook = openhook
def __del__(self):
self.close()
@@ -332,7 +339,10 @@
sys.stdout = self._output
else:
# This may raise IOError
- self._file = open(self._filename, self._mode)
+ if self._openhook:
+ self._file = self._openhook(self._filename, self._mode)
+ else:
+ self._file = open(self._filename, self._mode)
self._buffer = self._file.readlines(self._bufsize)
self._bufindex = 0
if not self._buffer:
@@ -364,6 +374,26 @@
def isstdin(self):
return self._isstdin
+
+def hook_compressed(filename, mode):
+ ext = os.path.splitext(filename)[1]
+ if ext == '.gz':
+ import gzip
+ return gzip.open(filename, mode)
+ elif ext == '.bz2':
+ import bz2
+ return bz2.BZ2File(filename, mode)
+ else:
+ return open(filename, mode)
+
+
+def hook_encoded(encoding):
+ import codecs
+ def openhook(filename, mode):
+ return codecs.open(filename, mode, encoding)
+ return openhook
+
+
def _test():
import getopt
inplace = 0
diff --git a/Lib/test/test_fileinput.py b/Lib/test/test_fileinput.py
index 4080a25..ff3fc24 100644
--- a/Lib/test/test_fileinput.py
+++ b/Lib/test/test_fileinput.py
@@ -6,7 +6,7 @@
from test.test_support import verify, verbose, TESTFN, TestFailed
import sys, os, re
from StringIO import StringIO
-from fileinput import FileInput
+from fileinput import FileInput, hook_encoded
# The fileinput module has 2 interfaces: the FileInput class which does
# all the work, and a few functions (input, etc.) that use a global _state
@@ -200,3 +200,25 @@
verify(lines == ["A\n", "B\n", "C\n", "D"])
finally:
remove_tempfiles(t1)
+
+if verbose:
+ print "18. Test file opening hook"
+try:
+ # cannot use openhook and inplace mode
+ fi = FileInput(inplace=1, openhook=lambda f,m: None)
+ raise TestFailed("FileInput should raise if both inplace "
+ "and openhook arguments are given")
+except ValueError:
+ pass
+try:
+ fi = FileInput(openhook=1)
+ raise TestFailed("FileInput should check openhook for being callable")
+except ValueError:
+ pass
+try:
+ t1 = writeTmp(1, ["A\nB"])
+ fi = FileInput(files=t1, openhook=hook_encoded("rot13"))
+ lines = list(fi)
+ verify(lines == ["N\n", "O"])
+finally:
+ remove_tempfiles(t1)