Address review comments

Explicitly check passwords for None rather than falsey.
Correct read_pdf documentation for Owner/User password.

Issue atlanhq#162

camelot/handlers.py

@@ -29,7 +29,7 @@ class PDFHandler(object):
     """
     def __init__(self, filename, pages='1', password=None):
         self.filename = filename
-        if password and sys.version_info[0] < 3:
+        if password is not None and sys.version_info[0] < 3:
             self.password = password.encode('ascii')
         else:
             self.password = password
@@ -59,7 +59,7 @@ def _get_pages(self, filename, pages):
             page_numbers.append({'start': 1, 'end': 1})
         else:
             infile = PdfFileReader(open(filename, 'rb'), strict=False)
-            if infile.isEncrypted and self.password:
+            if infile.isEncrypted and self.password is not None:
                 infile.decrypt(self.password)
             if pages == 'all':
                 page_numbers.append({'start': 1, 'end': infile.getNumPages()})
@@ -92,7 +92,7 @@ def _save_page(self, filename, page, temp):
         """
         with open(filename, 'rb') as fileobj:
             infile = PdfFileReader(fileobj, strict=False)
-            if infile.isEncrypted and self.password:
+            if infile.isEncrypted and self.password is not None:
                 infile.decrypt(self.password)
             fpath = os.path.join(temp, 'page-{0}.pdf'.format(page))
             froot, fext = os.path.splitext(fpath)
@@ -111,7 +111,7 @@ def _save_page(self, filename, page, temp):
                 fpath_new = ''.join([froot.replace('page', 'p'), '_rotated', fext])
                 os.rename(fpath, fpath_new)
                 infile = PdfFileReader(open(fpath_new, 'rb'), strict=False)
-                if infile.isEncrypted and self.password:
+                if infile.isEncrypted and self.password is not None:
                     infile.decrypt(self.password)
                 outfile = PdfFileWriter()
                 p = infile.getPage(0)

camelot/io.py

@@ -79,7 +79,7 @@ def read_pdf(filepath, pages='1', flavor='lattice', suppress_warnings=False,
         PDFMiner char_margin, line_margin and word_margin.
 
         For more information, refer `PDFMiner docs <https://euske.github.io/pdfminer/>`_.
-    password* : str, optional (default: None)
+    password : str, optional (default: None)
         Owner or User password required for file decryption.
 
     Returns