TST: Increase Test coverage (#756)

Adding unit Tests:

* xmp
* ConvertFunctionsToVirtualList
* PyPDF2.utils.hexStr
* Page operations with encoded file
* merging encrypted
* images

DOC: Comments to docstrings
STY: Remove vim comments

BUG: CCITTFaxDecode decodeParms can be an ArrayObject. 
          I don't know how a good solution would look like. Now it doesn't throw an error, but the result might be wrong.
BUG: struct was not imported for Python 2.X

Author: MartinThoma

PyPDF2/filters.py

@@ -1,5 +1,3 @@
-# vim: sw=4:expandtab:foldmethod=marker
-#
 # Copyright (c) 2006, Mathieu Fenniak
 # All rights reserved.
 #
@@ -40,7 +38,7 @@
     from cStringIO import StringIO
 else:
     from io import StringIO
-    import struct
+import struct
 
 try:
     import zlib
@@ -356,6 +354,10 @@ def decode(data, decodeParms=None):
 class CCITTFaxDecode(object):
     def decode(data, decodeParms=None, height=0):
         if decodeParms:
+            from PyPDF2.generic import ArrayObject
+            if isinstance(decodeParms, ArrayObject):
+                if len(decodeParms) == 1:
+                    decodeParms = decodeParms[0]
             if decodeParms.get("/K", 1) == -1:
                 CCITTgroup = 4
             else:
@@ -451,6 +453,10 @@ def _xobj_to_image(x_object_obj):
             img_byte_arr = io.BytesIO()
             img.save(img_byte_arr, format="PNG")
             data = img_byte_arr.getvalue()
+        elif x_object_obj["/Filter"] in (["/LZWDecode"], ['/ASCII85Decode'], ['/CCITTFaxDecode']):
+            from PyPDF2.utils import b_
+            extension = ".png"
+            data = b_(data)
         elif x_object_obj["/Filter"] == "/DCTDecode":
             extension = ".jpg"
         elif x_object_obj["/Filter"] == "/JPXDecode":

PyPDF2/generic.py

@@ -44,6 +44,8 @@
 import decimal
 import codecs
 
+from PyPDF2.utils import ERR_STREAM_TRUNCATED_PREMATURELY
+
 ObjectPrefix = b_('/<[tf(n%')
 NumberSigns = b_('+-')
 IndirectPattern = re.compile(b_(r"[+-]?(\d+)\s+(\d+)\s+R[^a-zA-Z]"))
@@ -199,17 +201,15 @@ def readFromStream(stream, pdf):
         while True:
             tok = stream.read(1)
             if not tok:
-                # stream has truncated prematurely
-                raise PdfStreamError("Stream has ended unexpectedly")
+                raise PdfStreamError(ERR_STREAM_TRUNCATED_PREMATURELY)
             if tok.isspace():
                 break
             idnum += tok
         generation = b_("")
         while True:
             tok = stream.read(1)
             if not tok:
-                # stream has truncated prematurely
-                raise PdfStreamError("Stream has ended unexpectedly")
+                raise PdfStreamError(ERR_STREAM_TRUNCATED_PREMATURELY)
             if tok.isspace():
                 if not generation:
                     continue
@@ -273,10 +273,11 @@ def readFromStream(stream):
     readFromStream = staticmethod(readFromStream)
 
 
-##
-# Given a string (either a "str" or "unicode"), create a ByteStringObject or a
-# TextStringObject to represent the string.
 def createStringObject(string):
+    """
+    Given a string (either a "str" or "unicode"), create a ByteStringObject or a
+    TextStringObject to represent the string.
+    """
     if isinstance(string, utils.string_type):
         return TextStringObject(string)
     elif isinstance(string, utils.bytes_type):
@@ -306,8 +307,7 @@ def readHexStringFromStream(stream):
     while True:
         tok = readNonWhitespace(stream)
         if not tok:
-            # stream has truncated prematurely
-            raise PdfStreamError("Stream has ended unexpectedly")
+            raise PdfStreamError(ERR_STREAM_TRUNCATED_PREMATURELY)
         if tok == b_(">"):
             break
         x += tok
@@ -328,8 +328,7 @@ def readStringFromStream(stream):
     while True:
         tok = stream.read(1)
         if not tok:
-            # stream has truncated prematurely
-            raise PdfStreamError("Stream has ended unexpectedly")
+            raise PdfStreamError(ERR_STREAM_TRUNCATED_PREMATURELY)
         if tok == b_("("):
             parens += 1
         elif tok == b_(")"):
@@ -392,16 +391,17 @@ def readStringFromStream(stream):
     return createStringObject(txt)
 
 
-##
-# Represents a string object where the text encoding could not be determined.
-# This occurs quite often, as the PDF spec doesn't provide an alternate way to
-# represent strings -- for example, the encryption data stored in files (like
-# /O) is clearly not text, but is still stored in a "String" object.
 class ByteStringObject(utils.bytes_type, PdfObject):
+    """
+    Represents a string object where the text encoding could not be determined.
+    This occurs quite often, as the PDF spec doesn't provide an alternate way to
+    represent strings -- for example, the encryption data stored in files (like
+    /O) is clearly not text, but is still stored in a "String" object.
+    """
 
     ##
     # For compatibility with TextStringObject.original_bytes.  This method
-    # returns self.
+    #  self.
     original_bytes = property(lambda self: self)
 
     def writeToStream(self, stream, encryption_key):
@@ -413,12 +413,14 @@ def writeToStream(self, stream, encryption_key):
         stream.write(b_(">"))
 
 
-##
-# Represents a string object that has been decoded into a real unicode string.
-# If read from a PDF document, this string appeared to match the
-# PDFDocEncoding, or contained a UTF-16BE BOM mark to cause UTF-16 decoding to
-# occur.
 class TextStringObject(utils.string_type, PdfObject):
+    """
+    Represents a string object that has been decoded into a real unicode string.
+    If read from a PDF document, this string appeared to match the
+    PDFDocEncoding, or contained a UTF-16BE BOM mark to cause UTF-16 decoding to
+    occur.
+    """
+
     autodetect_pdfdocencoding = False
     autodetect_utf16 = False
 
@@ -569,8 +571,7 @@ def readFromStream(stream, pdf):
                 skipOverComment(stream)
                 continue
             if not tok:
-                # stream has truncated prematurely
-                raise PdfStreamError("Stream has ended unexpectedly")
+                raise PdfStreamError(ERR_STREAM_TRUNCATED_PREMATURELY)
 
             if debug: print(("Tok:", tok))
             if tok == b_(">"):

PyPDF2/merger.py

@@ -1,5 +1,3 @@
-# vim: sw=4:expandtab:foldmethod=marker
-#
 # Copyright (c) 2006, Mathieu Fenniak
 # All rights reserved.
 #

PyPDF2/pdf.py

@@ -1,7 +1,5 @@
 # -*- coding: utf-8 -*-
 #
-# vim: sw=4:expandtab:foldmethod=marker
-#
 # Copyright (c) 2006, Mathieu Fenniak
 # Copyright (c) 2007, Ashish Kulkarni <[email protected]>
 #
@@ -1637,7 +1635,7 @@ def _getObjectFromStream(self, indirectReference):
                 streamData.seek(0, 0)
                 lines = streamData.readlines()
                 for i in range(0, len(lines)):
-                    print((lines[i]))
+                    print(lines[i])
                 streamData.seek(pos, 0)
             try:
                 obj = readObject(streamData, self)
@@ -2588,11 +2586,6 @@ def mergeRotatedScaledTranslatedPage(self, page2, rotation, scale, tx, ty, expan
                                                  ctm[1][0], ctm[1][1],
                                                  ctm[2][0], ctm[2][1]], expand)
 
-    ##
-    # Applys a transformation matrix the page.
-    #
-    # @param ctm   A 6 elements tuple containing the operands of the
-    #              transformation matrix
     def addTransformation(self, ctm):
         """
         Applies a transformation matrix to the page.

PyPDF2/utils.py

@@ -39,7 +39,7 @@
 except ImportError:  # Py3
     import builtins
 
-
+ERR_STREAM_TRUNCATED_PREMATURELY = "Stream has ended unexpectedly"
 xrange_fn = getattr(builtins, "xrange", range)
 _basestring = getattr(builtins, "basestring", str)
 
@@ -122,7 +122,7 @@ def skipOverComment(stream):
 def readUntilRegex(stream, regex, ignore_eof=False):
     """
     Reads until the regular expression pattern matched (ignore the match)
-    Raise PdfStreamError on premature end-of-file.
+    :raises PdfStreamError: on premature end-of-file
     :param bool ignore_eof: If true, ignore end-of-line and return immediately
     """
     name = b_('')
@@ -133,7 +133,7 @@ def readUntilRegex(stream, regex, ignore_eof=False):
             if ignore_eof:
                 return name
             else:
-                raise PdfStreamError("Stream has ended unexpectedly")
+                raise PdfStreamError(ERR_STREAM_TRUNCATED_PREMATURELY)
         m = regex.search(tok)
         if m is not None:
             name += tok[:m.start()]
@@ -242,7 +242,6 @@ def b_(s):
                     bc[s] = r
                 return r
             except Exception:
-                print(s)
                 r = s.encode('utf-8')
                 if len(s) < 2:
                     bc[s] = r