testing against None with "is", not using "=="

git-svn-id: https://pdfminerr.googlecode.com/svn/trunk/pdfminer@153 1aa58f4a-7d42-0410-adbc-911cccaed67c

pdfminer/pdffont.py

@@ -513,12 +513,12 @@ class PDFCIDFont(PDFFont):
             dic = {}
             char1 = char2 = None
             for v in seq:
-                if char1 == None:
+                if char1 is None:
                     char1 = v
-                elif char2 == None and isinstance(v, int):
+                elif char2 is None and isinstance(v, int):
                     char2 = v
                 else:
-                    if char2 == None:
+                    if char2 is None:
                         for (i,w) in enumerate(v):
                             dic[char1+i] = w
                     else:

pdfminer/pdftypes.py

@@ -177,7 +177,7 @@ class PDFStream(PDFObject):
         raise Exception, "zlib.error while decompressing data"
 
     def decode(self):
-        assert self.data == None and self.rawdata != None
+        assert self.data is None and self.rawdata != None
         data = self.rawdata
         if self.decipher:
             # Handle encryption
@@ -231,7 +231,7 @@ class PDFStream(PDFObject):
         return
 
     def get_data(self):
-        if self.data == None:
+        if self.data is None:
             self.decode()
         return self.data
 

pdfminer/pycdb.py

@@ -90,7 +90,7 @@ class CDBReader(object):
         (pos_bucket, ncells) = self._hash0[h1]
         if ncells == 0: raise KeyError(k)
         hs = self._hash1[h1]
-        if hs == None:
+        if hs is None:
             self._fp.seek(pos_bucket)
             hs = decode(self._fp.read(ncells * 8))
             self._hash1[h1] = hs

pdfminer/utils.py

@@ -33,7 +33,7 @@ def pick(seq, func, maxobj=None):
     maxscore = None
     for obj in seq:
         score = func(obj)
-        if maxscore == None or maxscore < score:
+        if maxscore is None or maxscore < score:
             (maxscore,maxobj) = (score,obj)
     return maxobj
 

tools/dumppdf.py

@@ -83,7 +83,7 @@ def dumpallobjs(out, doc, codec=None):
         for objid in xref.objids():
             try:
                 obj = doc.getobj(objid)
-                if obj == None: continue
+                if obj is None: continue
                 out.write('<object id="%d">\n' % objid)
                 dumpxml(out, obj, codec=codec)
                 out.write('\n</object>\n\n')