[Python-checkins] r67947 - in python/branches/py3k: Doc/library/zipfile.rst Lib/test/test_zipfile.py Lib/zipfile.py Misc/NEWS

[antoine.pitrou]

Author: antoine.pitrou
Date: Sat Dec 27 16:50:40 2008
New Revision: 67947

Log:
Merged revisions 67946 via svnmerge from 
svn+ssh://pythondev@svn.python.org/python/trunk

........
  r67946 | antoine.pitrou | 2008-12-27 16:43:12 +0100 (sam., 27 déc. 2008) | 4 lines
  
  Issue #4756: zipfile.is_zipfile() now supports file-like objects.
  Patch by Gabriel Genellina.
........


Modified:
   python/branches/py3k/   (props changed)
   python/branches/py3k/Doc/library/zipfile.rst
   python/branches/py3k/Lib/test/test_zipfile.py
   python/branches/py3k/Lib/zipfile.py
   python/branches/py3k/Misc/NEWS

Modified: python/branches/py3k/Doc/library/zipfile.rst
==============================================================================
--- python/branches/py3k/Doc/library/zipfile.rst	(original)
+++ python/branches/py3k/Doc/library/zipfile.rst	Sat Dec 27 16:50:40 2008
@@ -64,9 +64,11 @@
 .. function:: is_zipfile(filename)
 
    Returns ``True`` if *filename* is a valid ZIP file based on its magic number,
-   otherwise returns ``False``.  This module does not currently handle ZIP files
-   which have appended comments.
+   otherwise returns ``False``.  *filename* may be a file or file-like object too.
+   This module does not currently handle ZIP files which have appended comments.
 
+   .. versionchanged:: 2.7
+   Support for file and file-like objects.
 
 .. data:: ZIP_STORED
 

Modified: python/branches/py3k/Lib/test/test_zipfile.py
==============================================================================
--- python/branches/py3k/Lib/test/test_zipfile.py	(original)
+++ python/branches/py3k/Lib/test/test_zipfile.py	Sat Dec 27 16:50:40 2008
@@ -621,20 +621,49 @@
     def testIsZipErroneousFile(self):
         # This test checks that the is_zipfile function correctly identifies
         # a file that is not a zip file
-        fp = open(TESTFN, "w")
-        fp.write("this is not a legal zip file\n")
-        fp.close()
+
+        # - passing a filename
+        with open(TESTFN, "w") as fp:
+            fp.write("this is not a legal zip file\n")
         chk = zipfile.is_zipfile(TESTFN)
-        self.assert_(chk is False)
+        self.assert_(not chk)
+        # - passing a file object
+        with open(TESTFN, "rb") as fp:
+            chk = zipfile.is_zipfile(fp)
+            self.assert_(not chk)
+        # - passing a file-like object
+        fp = io.BytesIO()
+        fp.write(b"this is not a legal zip file\n")
+        chk = zipfile.is_zipfile(fp)
+        self.assert_(not chk)
+        fp.seek(0,0)
+        chk = zipfile.is_zipfile(fp)
+        self.assert_(not chk)
 
     def testIsZipValidFile(self):
         # This test checks that the is_zipfile function correctly identifies
         # a file that is a zip file
+
+        # - passing a filename
         zipf = zipfile.ZipFile(TESTFN, mode="w")
         zipf.writestr("foo.txt", b"O, for a Muse of Fire!")
         zipf.close()
         chk = zipfile.is_zipfile(TESTFN)
-        self.assert_(chk is True)
+        self.assert_(chk)
+        # - passing a file object
+        with open(TESTFN, "rb") as fp:
+            chk = zipfile.is_zipfile(fp)
+            self.assert_(chk)
+            fp.seek(0,0)
+            zip_contents = fp.read()
+        # - passing a file-like object
+        fp = io.BytesIO()
+        fp.write(zip_contents)
+        chk = zipfile.is_zipfile(fp)
+        self.assert_(chk)
+        fp.seek(0,0)
+        chk = zipfile.is_zipfile(fp)
+        self.assert_(chk)
 
     def testNonExistentFileRaisesIOError(self):
         # make sure we don't raise an AttributeError when a partially-constructed

Modified: python/branches/py3k/Lib/zipfile.py
==============================================================================
--- python/branches/py3k/Lib/zipfile.py	(original)
+++ python/branches/py3k/Lib/zipfile.py	Sat Dec 27 16:50:40 2008
@@ -130,18 +130,30 @@
 _CD64_DIRECTORY_SIZE = 8
 _CD64_OFFSET_START_CENTDIR = 9
 
-def is_zipfile(filename):
-    """Quickly see if file is a ZIP file by checking the magic number."""
+def _check_zipfile(fp):
     try:
-        fpin = io.open(filename, "rb")
-        endrec = _EndRecData(fpin)
-        fpin.close()
-        if endrec:
-            return True                 # file has correct magic number
+        if _EndRecData(fp):
+            return True         # file has correct magic number
     except IOError:
         pass
     return False
 
+def is_zipfile(filename):
+    """Quickly see if a file is a ZIP file by checking the magic number.
+
+    The filename argument may be a file or file-like object too.
+    """
+    result = False
+    try:
+        if hasattr(filename, "read"):
+            result = _check_zipfile(fp=filename)
+        else:
+            with open(filename, "rb") as fp:
+                result = _check_zipfile(fp)
+    except IOError:
+        pass
+    return result
+
 def _EndRecData64(fpin, offset, endrec):
     """
     Read the ZIP64 end-of-archive records and use that to update endrec

Modified: python/branches/py3k/Misc/NEWS
==============================================================================
--- python/branches/py3k/Misc/NEWS	(original)
+++ python/branches/py3k/Misc/NEWS	Sat Dec 27 16:50:40 2008
@@ -59,6 +59,9 @@
 Library
 -------
 
+- Issue #4756: zipfile.is_zipfile() now supports file-like objects. Patch by
+  Gabriel Genellina.
+
 - Issue #4574: reading an UTF16-encoded text file crashes if \r on 64-char
   boundary.