STY: Add error module (#768)

.isort.cfg

@@ -0,0 +1,6 @@
+[settings]
+line_length=79
+indent='    '
+multi_line_output=3
+length_sort=0
+include_trailing_comma=True

PyPDF2/errors.py

@@ -0,0 +1,25 @@
+class PyPdfError(Exception):
+    pass
+
+
+class PdfReadError(PyPdfError):
+    pass
+
+
+class PageSizeNotDefinedError(PyPdfError):
+    pass
+
+
+class PdfReadWarning(UserWarning):
+    pass
+
+
+class PdfStreamError(PdfReadError):
+    pass
+
+
+class ParseError(Exception):
+    pass
+
+
+STREAM_TRUNCATED_PREMATURELY = "Stream has ended unexpectedly"

PyPDF2/filters.py

@@ -40,8 +40,8 @@
 from PyPDF2.constants import ImageAttributes as IA
 from PyPDF2.constants import LzwFilterParameters as LZW
 from PyPDF2.constants import StreamAttributes as SA
-
-from .utils import PdfReadError, ord_, paethPredictor
+from PyPDF2.errors import PdfReadError
+from PyPDF2.utils import ord_, paethPredictor
 
 if version_info < ( 3, 0 ):
     from cStringIO import StringIO

PyPDF2/generic.py

@@ -39,11 +39,22 @@
 
 from PyPDF2.constants import FilterTypes as FT
 from PyPDF2.constants import StreamAttributes as SA
-from PyPDF2.utils import ERR_STREAM_TRUNCATED_PREMATURELY
+from PyPDF2.errors import (
+    STREAM_TRUNCATED_PREMATURELY,
+    PdfReadError,
+    PdfStreamError,
+)
 
 from . import filters, utils
-from .utils import (PdfStreamError, RC4_encrypt, b_, chr_, ord_,
-                    readNonWhitespace, skipOverComment, u_)
+from .utils import (
+    RC4_encrypt,
+    b_,
+    chr_,
+    ord_,
+    readNonWhitespace,
+    skipOverComment,
+    u_,
+)
 
 ObjectPrefix = b_('/<[tf(n%')
 NumberSigns = b_('+-')
@@ -111,7 +122,7 @@ def writeToStream(self, stream, encryption_key):
     def readFromStream(stream):
         nulltxt = stream.read(4)
         if nulltxt != b_("null"):
-            raise utils.PdfReadError("Could not read Null object")
+            raise PdfReadError("Could not read Null object")
         return NullObject()
     readFromStream = staticmethod(readFromStream)  # type: ignore
 
@@ -134,7 +145,7 @@ def readFromStream(stream):
             stream.read(1)
             return BooleanObject(False)
         else:
-            raise utils.PdfReadError('Could not read Boolean object')
+            raise PdfReadError('Could not read Boolean object')
     readFromStream = staticmethod(readFromStream)  # type: ignore
 
 
@@ -150,7 +161,7 @@ def readFromStream(stream, pdf):
         arr = ArrayObject()
         tmp = stream.read(1)
         if tmp != b_("["):
-            raise utils.PdfReadError("Could not read array")
+            raise PdfReadError("Could not read array")
         while True:
             # skip leading whitespace
             tok = stream.read(1)
@@ -200,23 +211,23 @@ def readFromStream(stream, pdf):
         while True:
             tok = stream.read(1)
             if not tok:
-                raise PdfStreamError(ERR_STREAM_TRUNCATED_PREMATURELY)
+                raise PdfStreamError(STREAM_TRUNCATED_PREMATURELY)
             if tok.isspace():
                 break
             idnum += tok
         generation = b_("")
         while True:
             tok = stream.read(1)
             if not tok:
-                raise PdfStreamError(ERR_STREAM_TRUNCATED_PREMATURELY)
+                raise PdfStreamError(STREAM_TRUNCATED_PREMATURELY)
             if tok.isspace():
                 if not generation:
                     continue
                 break
             generation += tok
         r = readNonWhitespace(stream)
         if r != b_("R"):
-            raise utils.PdfReadError("Error reading indirect object reference at byte %s" % utils.hexStr(stream.tell()))
+            raise PdfReadError("Error reading indirect object reference at byte %s" % utils.hexStr(stream.tell()))
         return IndirectObject(int(idnum), int(generation), pdf)
     readFromStream = staticmethod(readFromStream)  # type: ignore
 
@@ -306,7 +317,7 @@ def readHexStringFromStream(stream):
     while True:
         tok = readNonWhitespace(stream)
         if not tok:
-            raise PdfStreamError(ERR_STREAM_TRUNCATED_PREMATURELY)
+            raise PdfStreamError(STREAM_TRUNCATED_PREMATURELY)
         if tok == b_(">"):
             break
         x += tok
@@ -327,7 +338,7 @@ def readStringFromStream(stream):
     while True:
         tok = stream.read(1)
         if not tok:
-            raise PdfStreamError(ERR_STREAM_TRUNCATED_PREMATURELY)
+            raise PdfStreamError(STREAM_TRUNCATED_PREMATURELY)
         if tok == b_("("):
             parens += 1
         elif tok == b_(")"):
@@ -385,7 +396,7 @@ def readStringFromStream(stream):
                     # line break was escaped:
                     tok = b_('')
                 else:
-                    raise utils.PdfReadError(r"Unexpected escaped string: %s" % tok)
+                    raise PdfReadError(r"Unexpected escaped string: %s" % tok)
         txt += tok
     return createStringObject(txt)
 
@@ -477,7 +488,7 @@ def readFromStream(stream, pdf):
         if debug: print((stream.tell()))
         name = stream.read(1)
         if name != NameObject.surfix:
-            raise utils.PdfReadError("name read error")
+            raise PdfReadError("name read error")
         name += utils.readUntilRegex(stream, NameObject.delimiterPattern,
             ignore_eof=True)
         if debug: print(name)
@@ -494,7 +505,7 @@ def readFromStream(stream, pdf):
                 warnings.warn("Illegal character in Name Object", utils.PdfReadWarning)
                 return NameObject(name)
             else:
-                raise utils.PdfReadError("Illegal character in Name Object")
+                raise PdfReadError("Illegal character in Name Object")
 
     readFromStream = staticmethod(readFromStream)  # type: ignore
 
@@ -559,7 +570,7 @@ def readFromStream(stream, pdf):
         debug = False
         tmp = stream.read(2)
         if tmp != b_("<<"):
-            raise utils.PdfReadError("Dictionary read error at byte %s: stream must begin with '<<'" % utils.hexStr(stream.tell()))
+            raise PdfReadError("Dictionary read error at byte %s: stream must begin with '<<'" % utils.hexStr(stream.tell()))
         data = {}
         while True:
             tok = readNonWhitespace(stream)
@@ -570,7 +581,7 @@ def readFromStream(stream, pdf):
                 skipOverComment(stream)
                 continue
             if not tok:
-                raise PdfStreamError(ERR_STREAM_TRUNCATED_PREMATURELY)
+                raise PdfStreamError(STREAM_TRUNCATED_PREMATURELY)
 
             if debug: print(("Tok:", tok))
             if tok == b_(">"):
@@ -585,7 +596,7 @@ def readFromStream(stream, pdf):
                 data[key] = value
             elif pdf.strict:
                 # multiple definitions of key not permitted
-                raise utils.PdfReadError("Multiple definitions in dictionary at byte %s for key %s" \
+                raise PdfReadError("Multiple definitions in dictionary at byte %s for key %s" \
                                            % (utils.hexStr(stream.tell()), key))
             else:
                 warnings.warn("Multiple definitions in dictionary at byte %s for key %s" \
@@ -632,7 +643,7 @@ def readFromStream(stream, pdf):
                     data["__streamdata__"] = data["__streamdata__"][:-1]
                 else:
                     stream.seek(pos, 0)
-                    raise utils.PdfReadError("Unable to find 'endstream' marker after stream at byte %s." % utils.hexStr(stream.tell()))
+                    raise PdfReadError("Unable to find 'endstream' marker after stream at byte %s." % utils.hexStr(stream.tell()))
         else:
             stream.seek(pos, 0)
         if "__streamdata__" in data:
@@ -849,7 +860,7 @@ def getData(self):
             return decoded._data
 
     def setData(self, data):
-        raise utils.PdfReadError("Creating EncodedStreamObject is not currently supported")
+        raise PdfReadError("Creating EncodedStreamObject is not currently supported")
 
 
 class RectangleObject(ArrayObject):
@@ -1079,7 +1090,7 @@ def __init__(self, title, page, typ, *args):
         elif typ in [TF.FIT, TF.FIT_B]:
             pass
         else:
-            raise utils.PdfReadError("Unknown Destination Type: %r" % typ)
+            raise PdfReadError("Unknown Destination Type: %r" % typ)
 
     def getDestArray(self):
         return ArrayObject([self.raw_get('/Page'), self['/Type']] + [self[x] for x in ['/Left', '/Bottom', '/Right', '/Top', '/Zoom'] if x in self])

PyPDF2/pagerange.py

@@ -9,15 +9,16 @@
 
 import re
 
+from PyPDF2.errors import ParseError
+
 from .utils import isString
 
 _INT_RE = r"(0|-?[1-9]\d*)"  # A decimal int, don't allow "-0".
 PAGE_RANGE_RE = "^({int}|({int}?(:{int}?(:{int}?)?)))$".format(int=_INT_RE)
 # groups:         12     34     5 6     7 8
 
 
-class ParseError(Exception):
-    pass
+
 
 
 PAGE_RANGE_HELP = """Remember, page indices start with zero.