Python 3 compatibility Frappe test fixes (#4318)

* Read image file in binary mode

* Read files in binary mode

* Don't use bytestrings unnecessarily

* Correctly convert byte strings to unicode in frappe.as_unicode

* Convert content to bytes before writing to file

frappe/__init__.py

@@ -6,7 +6,7 @@ globals attached to frappe module
 """
 from __future__ import unicode_literals, print_function
 
-from six import iteritems, text_type, string_types
+from six import iteritems, binary_type, text_type, string_types
 from werkzeug.local import Local, release_local
 import os, sys, importlib, inspect, json
 
@@ -61,7 +61,7 @@ def as_unicode(text, encoding='utf-8'):
 		return text
 	elif text==None:
 		return ''
-	elif isinstance(text, string_types):
+	elif isinstance(text, binary_type):
 		return text_type(text, encoding)
 	else:
 		return text_type(text)

frappe/email/email_body.py

@@ -322,9 +322,9 @@ def add_attachment(fname, fcontent, content_type=None,
 	# Set the filename parameter
 	if fname:
 		attachment_type = 'inline' if inline else 'attachment'
-		part.add_header(b'Content-Disposition', attachment_type, filename=text_type(fname))
+		part.add_header('Content-Disposition', attachment_type, filename=text_type(fname))
 	if content_id:
-		part.add_header(b'Content-ID', '<{0}>'.format(content_id))
+		part.add_header('Content-ID', '<{0}>'.format(content_id))
 
 	parent.attach(part)
 
@@ -415,7 +415,7 @@ def get_filecontent_from_path(path):
 		full_path = path
 
 	if os.path.exists(full_path):
-		with open(full_path) as f:
+		with open(full_path, 'rb') as f:
 			filecontent = f.read()
 
 		return filecontent

frappe/email/test_email_body.py

@@ -21,9 +21,9 @@ This is the text version of this email
 '''
 
 		img_path = os.path.abspath('assets/frappe/images/favicon.png')
-		with open(img_path) as f:
+		with open(img_path, 'rb') as f:
 			img_content = f.read()
-			img_base64 = base64.b64encode(img_content)
+			img_base64 = base64.b64encode(img_content).decode()
 
 		# email body keeps 76 characters on one line
 		self.img_base64 = fixed_column_width(img_base64, 76)

frappe/utils/file_manager.py

@@ -191,7 +191,9 @@ def write_file(content, fname, is_private=0):
 	# create directory (if not exists)
 	frappe.create_folder(file_path)
 	# write the file
-	with open(os.path.join(file_path.encode('utf-8'), fname.encode('utf-8')), 'w+') as f:
+	if isinstance(content, text_type):
+		content = content.encode()
+	with open(os.path.join(file_path.encode('utf-8'), fname.encode('utf-8')), 'wb+') as f:
 		f.write(content)
 
 	return get_files_path(fname, is_private=is_private)